Harry Potter Wiki
Harry Potter Wiki
"As obsessive fans will tell you, I do slip up! Several classrooms move floors mysteriously between books and these are the least serious continuity errors! Most of the fansites will point you in the direction of my mistakes. But the essentials remain consistent from book to book because the story has been plotted for a long time and it is clear in my mind."
J. K. Rowling on the errors within the franchise[src]

Below is a list of mistakes that occur in the Harry Potter book series, such as factual errors, plot holes and typos. Some of these mistakes were fixed in later editions of the same book.[1]



  • Although Hogwarts's full name is Hogwarts School of Witchcraft and Wizardry, a distinction between "witchcraft" and "wizardry" has never been made, and the two seem to be just synonymous with the much more used term magic. However, there is a distinction between wizards and witches, which refers solely to their gender; thus, it is possible that "witchcraft" is magic performed by witches and "wizardry" is magic performed by wizards.
  • Although Hogwarts is said to have a reputation as one of the safest locations in the wizarding world, dangerous events happened with a relative frequency at the school during Harry's years. These included the troll roaming the dungeons in the first year, the Serpent of Slytherin's attacks on Muggle-borns in the second year, a Dementor attacking the Hogwarts Express in the third year, the Triwizard Tournament in the fourth year, and several events relating to the Second Wizarding War in later years. Also, Voldemort followers such as Quirinus Quirrell, Peter Pettigrew, and Barty Crouch Junior all resided in the school for long periods in disguise (or, in Quirrell's case, concealing their true intents), which also posed a significant danger to everyone, especially Harry Potter.
  • J. K. Rowling said in an interview that there are about one thousand students attending Hogwarts at any given time. However the books mention no more than five students of the same gender, House and year (for example, Harry is known to share a dormitory with only four other boys: Ron, Neville, Dean and Seamus). If this pattern is consistent across the whole school (5 boys and 5 girls per house per year), there would be a total of only around 280 students. If a total of a thousand students was equally divided, each dormitory per house per year would have about 17 to 18 boys or girls.
    • One theory is that Harry's year was an unusually small intake, due to the fact that the time at which those students would've been conceived was during the height of the First Wizarding War and many wizarding families may have been reluctant to bring children into the world at such a dangerous time.
    • It is also possible that there are more dormitories that don't appear in the books and films. The only ones mentioned in the books are the ones that house the students who are actually in the book, e.g. Harry, Ron, Neville, Hermione.

Date of Albus Dumbledore's death

  • Immediately before Harry receives Dumbledore's summons to accompany him on the Skirmish at the Cave (therefore, this was the very night Dumbledore died), Harry says he'll be doing detention that Saturday and the two Saturdays afterwards,[2] meaning there's at least 2-3 weeks until the end of the year, the date of which is firmly established in previous books to be around 30 June.[3][4] This places the date of the skirmish and the Battle of the Astronomy Tower (and therefore Dumbledore's death) sometime in early-to-mid June. There's also nothing to suggest that it was the last day of term, and the early-to-mid June timeframe also fits in with the O.W.L and N.E.W.T exams that were happening at the time.
  • The end of the year is stated to have happened a few chapters later, in The White Tomb.[5]
  • The school year cannot have run into July, as Harry is stated to have been at 4 Privet Drive for at least four weeks as of 27 July.[6][7] This means the school year ended at the end of June as normal. It is also known that there would have been at the very least a few days between Dumbledore's death and his funeral (and, in all likelihood, longer than that, as Dumbledore was such a high-profile person), after which the students were sent home.
  • All lessons and exams were cancelled or postponed due to his death,[5] meaning the school year was ongoing.
  • When Rufus Scrimgeour came to carry out Dumbledore's will on Harry's birthday (31 July), Harry states that Dumbledore died more than a month ago,[8] which means it would have been before 30 June, and even if 'a month' is taken to mean exactly 28 days, it still doesn't necessarily place it at 30 June; it could be any date before 3 July. 30 June, however, would contradict the above-mentioned statement about Harry being away from Hogwarts for at least four weeks (28 days) as of 27 July, as the students had gone home by then (30 June). In the same scene, it was stated that the 31 days (a month, in the sense of the same date in successive months, or in this case as close as possible) for the Decree for Justifiable Confiscation ended on that day,[8] meaning its triggering cannot have coincided with Dumbledore's death (this is the logic used for the 30 June date; it assumes the two happened at the same time, which there's no evidence of), but would have been some time afterwards, presumably when his will was found or when the Ministry seized the items. It is known that wills can take time to be found, as Sirius Black's will wasn't found until early July 1996,[9] even though he died in the middle of June.[10]
  • The Daily Prophet article DUMBLEDORE – THE TRUTH AT LAST?, published on 27 July, mentions that the book The Life and Lies of Albus Dumbledore was completed four weeks after Dumbledore's death.[11] This is sometimes taken to mean 27 July was the completion date for the book, which indeed leads back to 30 June being the date Dumbledore died. However, the article does not actually say this, just that the book was completed four weeks after his death. In fact, the context seems to suggest the book was completed before the article was written, which places the date of Dumbedore's death before 30 June.


  • The books mention several weekdays as having fallen on specific dates (which are known indirectly). However, many of them do not match the actual dates in real life. In particular, the day after the Start-of-Term Feast (i.e. 2 September) seems to be a Monday every year. A possible explanation is a slight calendar difference, either in-universe between the wizarding and Muggle worlds, or between the book world and the real world.
  • Much is made of Hagrid's innocence of attacking Muggle-borns, both from his time as a student and when he was taken to Azkaban as a precaution, but there were several offences that he should in fact have been charged with and wasn't, such as keeping a dragon as a pet, endangering students with some of the creatures in his class and breeding the Blast-Ended Skrewts.
  • The purchasing power of wizarding currency is incredibly inconsistent throughout the series. In the Chamber of Secrets, Molly Weasley is able to purchase supplies for all five of her school age children for one Galleon and 'a very small pile of silver Sickles', but in the Half-Blood Prince a copy of Advanced Potion-Making alone costs 9 Galleons. Furthermore, based on the prices on the Fantastic Beasts and Where to Find Them and Quidditch Through the Ages companion books, this would put the price of the potion book as nearly £45, which seems a lot for a mandatory secondary school textbook. (Although this may also be due to the fact that the book is likely to be imported from Brazil and later translated into English, since the author Libatius Borage, a famous South American potioneer, is a known alumnus of Castelobruxo.)

Harry Potter and the Philosopher's Stone


  • The art for the cover of the original UK edition depicts Harry at Platform Nine and Three-Quarters wearing a Gryffindor scarf. However, Harry hasn't been sorted yet. It is possible, however, that the illustration is of Harry returning to Little Whinging at the end of the school term (although given the look of surprise on Harry's face, this is unlikely as his expression would be more appropriate to seeing the train for the first time). Another explanation could be that this was the result of a coincidence in which he already owned a red and gold scarf at the Dursleys' house before starting at Hogwarts.
  • The cover art of the original UK edition depicts another train beside the Hogwarts Express. The train, which is meant to be an InterCity 125, is at a platform that High Speed Trains do not use, but does accurately depict the InterCity Swallow livery of the era.
  • The Bloomsbury Original Adult Edition cover depicts the Hogwarts Express as a Norfolk & Western J class (specifically #602), a class of streamlined steam locomotives that was used in the United States and would be too large for the British loading gauge.

Chapter 1: The Boy Who Lived

  • The beginning of the story takes place on a "dull, grey Tuesday." But in 1981, 1 November was on a Sunday.
  • The Muggle news reports an unusually large number of owls awake and flying around in the daytime. However, no mention is made that the owls are carrying packages or letters, which is the only reason so many of them would be out and about during daylight, and for that matter, would make for a much stranger (and therefore newsworthy) sighting by Muggle standards than just the fact that the owls are awake during the day.
  • It is very unclear how much time goes by between certain events on 31 October and 1 November. Sirius arrived on the scene at Godric's Hollow the night James and Lily died, and Hagrid arrived there a short while later. When Hagrid picks up Harry from Godric's Hollow early in the morning "right before the Muggles started swarmin' around" he borrows Sirius' motorbike. However, Hagrid arrives on the motorbike late to Privet Drive when it is "nearly midnight" the next day, having not spoken to Dumbledore since he went to go pick Harry up. As the chapter depicts a whole day between when James and Lily died and when Hagrid arrives at Privet Drive, Hagrid and Harry are missing, or unaccounted for, for nearly 24 hours.
  • It is unknown why Professor McGonagall was staying next to the Dursleys' home all day, instead of being at Hogwarts, tending to her duties as transfiguration teacher and head of Gryffindor House. It is highly unlikely that she was stationed there on Dumbledore's orders, as Dumbledore was surprised to see her there. It is also equally unlikely that she was there to see Harry be delivered to the Dursleys, as she was appalled when Dumbledore announced his intention to do that. The only thing she knew (as she heard this from Hagrid) was that Dumbledore was planning on going there, but she has no reason to keep tabs on Dumbledore, especially at the expense of her duties at Hogwarts.
  • Dumbledore says that he passed through several parties to get to Little Whinging, even though he apparently got there by Apparition, a direct form of transport, judging from his sudden appearance next to Minerva McGonagall. He could have Apparated several times to go to many parties – possibly in order to lose anyone (such as Death Eaters) who might have been following him. It is also possible he walked or flew most of the way, and only decided to Apparate a very short distance to Privet Drive, though what motive he would have for this is unknown.
  • In the Bloomsbury edition, on page 17, Hagrid says "I'll be takin' Sirius his bike back"; yet, in Harry Potter and the Prisoner of Azkaban, Sirius told Hagrid to keep the bike because he didn't need it anymore. It is, of course, possible that Hagrid intended to give the bike back in spite of his friend's protests, feeling Sirius may not have meant it. Still, in later editions of this book, the problem was fixed by having Hagrid say "I'd best get this bike away" instead.

Chapter 2: The Vanishing Glass

  • Piers Polkiss is described as "a scrawny boy with a face like a rat", but in another part of the book Dudley's gang is described as all being "big and stupid" with Dudley being the biggest and stupidest.
    • Possibly he was scrawny compared to the other gang members but still large compared to Harry who, at that time, was described as "small and skinny"
  • The trip to the zoo is said to take place on a Saturday, but Dudley's eleventh birthday (23 June, 1991) was actually on a Sunday.
  • The boa constrictor at the Zoo supposedly winked at Harry during their conversation. As snakes don't have eyelids in real life, it is impossible for them to wink. The snake may have been magical or have instead contracted its facial muscles around its eyes to appear to wink, though the possibility of even this is debatable. It is also possible, if unlikely, that snakes in the Harry Potter universe are slightly different from their real-world counterparts, which would go along with their apparent higher intelligence.
  • After Harry talks to the snake, Dudley says "You won't believe what this snake is doing", but if Harry had spoken Parseltongue Dudley should have said "You wont believe what Harry is doing"
    • Dudley might have thought that Harry was making sounds to imitate a snake.

Chapter 3: The Letters from No One

  • Harry's 11th birthday (31 July, 1991) was said to be on a Tuesday. But in 1991 in the real world, that date was a Wednesday.
  • On page 31, the sentence "Harry could see Uncle Vernon's shiny black shoes pacing up and down the kitchen" begins with a speech mark, even though the line is not being spoken by anyone. It is amended in later editions.

Chapter 4: The Keeper of the Keys

  • Hagrid tells Harry that "There's not a witch or wizard who went bad who wasn't in Slytherin." However, Peter Pettigrew betrayed Harry's parents and he was in Gryffindor. While Hagrid didn't know at the time that Pettigrew was the traitor, he did believe that Sirius was and he was also a Gryffindor, so Hagrid's statement is incorrect from either perspective.

Chapter 5: Diagon Alley

  • On Harry's Hogwarts list of school supplies, "1 Wand" is listed twice, as both the first and last item on the list. This mistake was fixed in later editions of the book. The list of school supplies also doesn't include potion ingredients, although Harry later buys them. In later editions of the book this has been corrected.
  • Harry buys the book One Thousand Magical Herbs and Fungi, but later, he looks up dittany in "One Hundred Magical Herbs and Fungi". This error was, however, amended in later editions.
  • The air in the tunnels of the Gringotts vaults is described as getting colder when you go deeper into the earth. However, in theory, it should get hotter as you go deeper as once you get below a level where the temperature depends heavily on the weather at the surface, the geothermal gradient takes over and it gets hotter as you go deeper. Of course, there may be enchantments in place to account for this discrepancy.
  • When Harry returns from Diagon Alley to Little Whinging, he takes a train from Paddington Station. However, Little Whinging is in Surrey, south of London, so he should have travelled from Victoria or Waterloo; trains from Paddington head to the west.
  • Despite Garrick Ollivander's claims that the original Ollivander arrived to Great Britain with the Romans, this individual started his wand-making business in 382 B.C. but the Roman conquest of Britain (Britannia) only began effectively in A.D. 43, under Emperor Claudius. An earlier attempt was made in 55-54 B.C. by Julius Caesar, as an adjunct of his Gallic campaign. Prior to then, the Romans had only sporadic contact with Britain, to the point where, up until 124 B.C., many Romans did not believe the land actually existed.

Chapter 6: The Journey from Platform Nine and Three-Quarters

  • Aunt Petunia is described as looking as surprised as the other Dursleys about Harry needing to board at Platform Nine and Three-Quarters, yet according to Harry Potter and the Deathly Hallows, she had been there at least once. However, she may have been pretending to be startled in order to distance herself from the magical world.
  • Mrs Weasley asks her children which platform the train departs from, but she should know this perfectly well, since she departed seven times from the same platform. However, it is possible she only asks so her children remember.
  • On page 79, the closing quotation mark is missing right after Hermione tells Harry about the books he is in. This mistake was fixed in later editions of the book.
  • King's Cross Station is described like St Pancras Station, instead of King’s Cross.

Chapter 7: The Sorting Hat

  • While being sorted into houses, Harry looks up at the Sorting Hat's stool, and there are only three people left to be sorted. Professor McGonagall then calls out the names of four more students. This error only occurred in the US edition and was rectified in later editions – in the UK edition Dean Thomas's name is omitted.
  • During the Sorting ceremony, Sally-Anne Perks is sorted before Harry but in Harry Potter and the Order of the Phoenix, when everyone in fifth year are being called in alphabetical order to take their practical O.W.L.s, Parvati Patil is called before Harry. It should actually have been Sally-Anne Perks, but because many students were pulled out of the school that year, it is possible that Sally-Anne was cut out.
  • When Harry first meets Nicholas de Mimsy-Porpington, the ghost says how he has not eaten in nearly 400 years. Yet he had, at the time, already been dead for 99 years longer than that. This was fixed in later editions of the book.
  • It was stated in a previous chapter that Harry's birthday, 31 July, was on a Tuesday (regardless of what day it actually fell on in 1991), which would mean that 1 September was on a Saturday. The next day would have been a Sunday, yet classes began.

Chapter 9: The Midnight Duel

  • Fred tells Harry that the Gryffindor Quidditch team hadn't won a championship "since Charlie left". Charlie attended Hogwarts from 1984-1991, and so had only just graduated as Harry arrived – Harry filled the seeker vacancy left by Charlie. It is a strange way to put it since no time had really passed since Charlie left, though Fred is still telling the truth as they hadn't won since 1986 which is when Charlie attended.
    • It is possible Charlie, while still at school, had left the Quidditch team a few years before actually leaving Hogwarts, which would fit with Professor McGonagall expressing the need for a better team than the previous year.

Chapter 10: Hallowe'en

  • During the Hallowe'en feast, when the troll is let in, Professor Dumbledore sends the students to their dormitories, but the troll is said to be in the dungeons, and that is also where the Slytherin dormitories are, meaning that Dumbledore has put them directly in harm's way by sending them there. The logical move would be for every student to stay in the Great Hall, do a roll call, and send teachers to go and look for missing students.

Chapter 11: Quidditch

  • The narrator says that if Gryffindor won the first Quidditch match, they would pull into second place for the House Cup. However, in Prisoner of Azkaban, the Hogwarts Quidditch tournament appears to have its own cup, independent of the House Cup.
    • It is possible that winning a Quidditch match gives points to the winning team's house.

Chapter 13: The Mirror of Erised

  • Dumbledore tells Harry that the Mirror of Erised 'gives us neither knowledge nor truth'. However, it does in the sense that it shows the viewer their deepest desire, even if they don't know what it is, thus giving them that knowledge.

Chapter 14: Norbert the Norwegian Ridgeback

  • The night Charlie's letter shows up at Hogwarts is said to be Wednesday at midnight. However, earlier in the book it is mentioned that Astronomy classes take place every Wednesday at midnight which means that they are presumably skipping class, and the other students should not be asleep. Later editions have changed the day of Charlie's visit to Saturday.
  • Curiously, McGonagall takes fifty Points from Harry, Neville and Hermione for wandering around the halls at night, but she only takes twenty from Draco Malfoy for committing the same offence. Earlier in the book, she takes only five Points from Hermione for her allegedly going to fight a mountain troll on her own.

Chapter 16: Through the Trapdoor

  • During the match against the giant chess set, Ron says "Well, Harry, you take the place of that bishop, and Hermione, you go next to him instead of that castle." Except the castle is next to the knight, not the bishop. It is possible though that when Ron said "next to him" he didn't mean immediately next to, only in the general area of where Harry was located.
  • Also in the match, Harry was acting as the bishop. His last move was to move three spaces to the left. However, in real chess bishops can only move diagonally. However, it could also mean that Harry simply moved 3 spaces left diagonally, and wasn't written properly.
  • At the beginning of the same match, Ron is the knight in the giant chess set. It later says that he had to "move ahead one" so that the Queen could take him, opening the path for Harry to checkmate the king, and win the match. If he were a knight, he would only be able to move either ahead one, and sideways two, or ahead two, and sideways one. It is possible, however, that "one" was meant as one move, rather than one space.
  • When Harry and Hermione drink the two potions to get them through Snape's task, there is only one bottle to get them through the black fire and only one bottle to get them through the purple fire. The smallest bottle holds the potion for the black fire, and it only contains enough for one person. If this is so, then it is unknown how Quirrell got to the Mirror of Erised in the first place.
    • Although, it's possible that the task just reappears again, just like the chess set was intact and Harry, Ron and Hermione had to play the game again.
    • It is also possible that Quirrell had only taken a sip of the potion himself, therefore only leaving enough for one more person.
  • If Dumbledore's letter from the Ministry really was urgent, it seems odd that he would choose to fly all the hundreds of miles there rather than get there almost instantly by Floo powder or Apparition (though the former had yet to be introduced). He could have done that and seen right away that it was a trick, so Quirrel and Voldemort's scheme to lure him away by falsifying business with the Ministry falls right apart.

Chapter 17: The Man with Two Faces

  • Dumbledore says that he and Hermione's owl crossed in mid-air. However, a few pages later Hermione says to Harry that she ran into Dumbledore on the way to the Owlery to send him the owl.
    • He actually says "We must have crossed in midair", indicating that he is making an assumption. Harry merely informed him of Hermione's intention to send an owl. Since Dumbledore is not omniscient (as he admits himself) the reason he'd assumed for why he hadn't received it may have been wrong, as he didn't know she hadn't sent it.
  • Dumbledore explains that only a person who wanted to find the Stone, but not use it, would be able to get it. However, by that logic, Quirrell should have been able to get the Stone without any problem, as he did not want to use the Stone himself, only present it to Voldemort.
    • It's possible that the Mirror regarded Voldemort and Quirrell as a single person as they were inhabiting the same body.
    • It's also possible that the Mirror knew that Quirrell wanted to give the Stone to Voldemort, which is still using it, just not on himself.
  • If nobody could acquire the Stone if they wanted to use it, then it is unclear how Nicolas Flamel was supposed to get it in order to make more Elixir of Life. Perhaps he had already decided that he was ready to die and had no desire to have the Stone anymore, but then, why didn't he and Dumbledore just destroy the Stone as soon as it was retrieved from Gringotts?
    • It is possible that Dumbledore would have lifted the spell if Flamel needed the Stone.
  • It is unknown why Dumbledore and/or Flamel could not have used the Fidelius Charm to hide the stone and/or its whereabouts.

Harry Potter and the Chamber of Secrets


  • The UK version of the cover illustration of Harry, Ron, and Hedwig in the flying Ford Anglia incorrectly depicts Hedwig as a barn owl rather than a snowy owl.
  • On the front cover of the Spanish edition, Harry is holding the sword and looking at the Basilisk, but looking into a Basilisk's eye's is fatal, so, technically, Harry should be dead on the Spanish front cover. However with Fawkes having clawed out the Basilisk's eyes, Harry would be able to look on without fear of death.

Chapter 2: Dobby's Warning

  • Petunia should have been aware that underage wizards and witches are not allowed to use magic outside of school, since the rule was written in 1875, well before Lily's time at Hogwarts. However, it could have been that Lily had simply forgotten to mention this to her. It should be noted that in book 1 during Harry's birthday, she claimed that Lily "turned teacups into rats".
  • The Ministry of Magic detected Dobby using the Hover Charm and assumed it was Harry. However, by that logic, they should have also detected the Disapparition Spell performed immediately after the Hovering Charm, and realised that this spell was far above the paygrade of a second-year student.
  • Sending an owl to deliver a letter, in the presence of two Muggles who did not know that wizards exist, ironically does far more to expose the existence of the wizarding world to Muggles than a spell that happened when those Muggles' backs were turned.

Chapter 3: The Burrow

  • After Harry, Ron, Fred, and George arrive at the Burrow, Mrs Weasley shouts at Fred first. Then she says, "and you two" glaring at Ron and Fred, but it should say George since she has already yelled at Fred. This error was corrected in later editions of the book.
  • In the US edition of the audiobook read by Jim Dale, Ginny's eyes are stated as being bright green but in the printed US first edition, and the UK version of the audiobook read by Stephen Fry, they are said to be bright brown, which agrees with the description in Harry Potter and the Deathly Hallows of Molly's eyes being the exact same shade of brown as Ginny's.

Chapter 4: At Flourish and Blotts

  • The Hogwarts equipment list mentions the Lockhart book "Wanderings with Werewolves", but later, Lockhart refers to the book as "Weekend with a Werewolf". This error was fixed in later editions of the same book.

Chapter 5: The Whomping Willow

  • When Harry and Ron arrive at Hogwarts in the flying Ford Anglia, a scene which takes place on 1 September, 1992, they are told that they had been seen by Muggles in various locations, including the "Post Office Tower". But due to a change of ownership, the tower has actually been called the BT Tower since 1984. Also, the building is about a mile southwest of King's Cross, so to pass it, Harry and Ron would have had to be going in an entirely different direction to be following the Hogwarts Express.

Chapter 8: The Deathday Party

  • Harry, Ron and Hermione go to Nearly Headless Nick's 500th deathday party. However, in the first book at the start of term feast he says he has not eaten for nearly 400 years, which would imply that this is how long he has been dead.
    • In later printings of the first book, Nick's comment is changed from "nearly 400 years" to "nearly 500 years".

Chapter 9: The Writing on the Wall

  • Hermione says that Moaning Myrtle haunts the bathroom on the first floor. However, when Harry sees the writing on the wall outside her bathroom, he is on the second floor.
  • It remains unknown how Moaning Myrtle never notices Ginny visiting her bathroom, or the pipe door opening, or the Basilisk coming through her bathroom.
  • Percy's name is once misspelled as Perry after he catches Harry, Ron and Hermione leaving Myrtle's bathroom.

Chapter 11: The Duelling Club

  • When brewing the Polyjuice Potion, Hermione says that she should steal the ingredients from Snape's stores, rather than Harry or Ron, as they will be expelled if they're caught, whereas her record is clean. However, that isn't entirely true, because she claimed to have gone looking for the troll in their first year and lost five points for it, plus she was caught out of bed the night that she and Harry sent Norbert to Charlie.
    • However, this might be related to the current school year, for which her record was actually clean. Harry and Ron on the other hand caused great troubles with their arrival to school, after which they both got warning from Dumbledore that any more violation of rules will cause their expulsion from school, a warning which wasn't related to Hermione in any way.
  • When Harry speaks Parseltongue to the snake during his duel with Draco, everyone hears him hissing. Therefore, when Harry hears the Basilisk speaking in the walls, Ron and Hermione should hear hissing, yet they claim to hear nothing.
    • A possible explanation for this could be that the Basilisk is hissing very quietly or is muffled by the pipes and the walls, so Ron and Hermione can barely hear it, but Harry can make out the words as he hears them in English.

Chapter 13: The Very Secret Diary

  • When Harry is viewing the memory from Tom Riddle's diary, Tom Riddle says to Hagrid at one point, "The dead girl's parents will be here tomorrow." It is stated elsewhere in the book that Myrtle is Muggle-born. Muggles cannot enter Hogwarts. However, it is possible that an exception was made for them (the Muggle-Repelling Charm could be lifted a day or two, for this reason), or it could be that Tom simply assumed that Myrtle's parents were wizards (although this is highly unlikely, since it is later revealed that he was the heir of Slytherin, and thus had personally sought to bring about Myrtle's death, meaning he must have known that she was a Muggle-born). Another possibility is that he may have been bluffing in order to scare Hagrid.
  • Valentine's Day in the book is depicted as a typical school day, albeit one where the cupid dressed dwarfs are interrupting classes. 14 February, 1993 was a Sunday, meaning there should have been no classes to interrupt.

Chapter 14: Cornelius Fudge

  • When Harry is at the Quidditch pitch, reflecting with relief that there will be no one in the castle to become victims of the monster of Slytherin, Professor McGonagall shows up to say that the monster has struck again, and that everyone should return to their dormitories, presumably to keep them safe. However, the students would have been far safer to remain at the pitch while the professors checked the castle again.
  • It is written that "Harry had inherited just one thing from his father: a long and silvery Invisibility Cloak". This is untrue, as we find out in Chapter 5, Diagon Alley in Harry Potter and the Philosopher's Stone, that Harry also inherited James and Lily's gold, kept at Gringotts.
    • This is probably intended to mean that he only inherited one actual item, as opposed to a commodity such as money.

Chapter 15: Aragog

  • When Harry tells Ron to be quiet or the 'something big' will hear them, Ron responds, "Hear *me*? It's already heard. Fang!" However the sentence should probably be "It's already heard Fang!" as it is read in the audiobooks. It is amended in later editions.

Chapter 16: The Chamber of Secrets

  • It is stated that the Basilisk was able to move through the castle's pipes, but it remains unknown how something as large as the Basilisk would be able to fit through the plumbing.
    • Based on the fact that Harry, Ron and Lockhart are able to move through the plumbing to get to the Chamber later on, it may be that the pipes for Hogwarts are simply that large, or may change shape depending on their load, just as the staircases can move.
  • It is unclear how Fawkes spoke Parseltongue to enter the Chamber of Secrets to intercede Harry, nor how Ron could have been strong enough to help him get past the rubble caused by Lockhart's spell.
    • It's likely that Fawkes simply Apparated past any barriers in his way, because it's known that phoenixes can disappear and reappear somewhere else naturally.

Chapter 17: The Heir of Slytherin

  • Tom Riddle states that Lily Potter's death bought Harry "twelve years of borrowed time". This is incorrect as he had not yet turned thirteen, and Lily died when he was one, and so it should be "eleven years of borrowed time".

Chapter 18: Dobby's Reward

  • On page 283 of some copies of both the US paperback and hardback editions, the word "professor" is misspelled as "professorr".
  • Dumbledore tells Harry that Lord Voldemort is the last remaining ancestor of Salazar Slytherin. This is meant to say that Lord Voldemort is the last remaining descendant of Salazar Slytherin.
    • This error was fixed in later editions of the book.
  • Dumbledore concedes that nobody will ever be able to prove that Lucius Malfoy slipped Tom Riddle's diary to Ginny before the start of term, let alone did so with the intention of opening the Chamber of Secrets; thus, Lucius could not be prosecuted. At the time Dumbledore says this, this is true. However, only a few minutes later, they suddenly have a witness they could have used against Malfoy: The newly freed Dobby! Bear in mind that, in Order of the Phoenix, Dumbledore offers to summon Dobby to give evidence in Harry's defence, and the Minister decided to accept Harry's version of events without needing the evidence. So clearly, house-elves are not considered incompetent witnesses by the Wizengamot.

Harry Potter and the Prisoner of Azkaban


Full Scholastic (US) cover and back cover art

Bloomsbury (UK) cover

  • On the US version of the cover, the front art is the night that Harry and Hermione save Sirius and Buckbeak. However, on the back side of the cover (Lupin appears as a werewolf), the moon is a crescent, but it should be a full moon.
  • The cover of the Scholastic edition and British Bloomsbury edition both depict Harry and Hermione riding Buckbeak. Harry's legs are shown to be in front of Buckbeak's wings, however, when Harry was in Care of Magical Creatures and rode Buckbeak for the first time, Hagrid had told him to sit behind the wing joint, as he did in the films. However, this may have been because Hermione is sitting behind him.
  • On the back cover of some editions, it said that Harry blew up his Aunt Petunia instead of Aunt Marge. This error was fixed in later editions of the same book.

Chapter 1: Owl Post

  • In earlier editions of the book, the first page stated that A History of Magic was written by Adalbert Waffling, rather than Bathilda Bagshot.
    • This was rectified in later editions of the same book.
  • When Harry is looking at his scar and how it came to be, the reader is informed that his parents had been murdered by the most feared dark wizard for a hundred years, Lord Voldemort. This is false; Voldemort was actually the most feared dark wizard of all time.
    • It may just be an instance of poetic licence.
  • In her letter accompanying the Broomstick Servicing Kit that she sent to Harry from France, Hermione expresses concern over the possibility of the package being opened at Customs. However, the UK was in the European Union in 1993, so there wouldn't have been any Customs checks on goods arriving from France.
    • It is possible that Hermione did not know that there wouldn’t have been a Customs check.

Chapter 2: Aunt Marge's Big Mistake

  • When Harry leaves the Dursley's house after blowing up Aunt Marge like a balloon, he, at least in that moment, has the intention of never returning to the Dursleys' home ever again. The bond of blood should have therefore been broken, making him fair game for Voldemort and/or the Death Eaters.
    • It is possible that he may have known deep down that he would end up returning, even if he didn't consciously want to at that moment.

Chapter 3: The Knight Bus

  • When Harry travels on the Knight Bus, 'Anglesey' is misspelled as 'Anglesea'.
  • When Hedwig greets Harry in the Leaky Cauldron, it says that she 'clicked her break' instead of 'beak'.

Chapter 4: The Leaky Cauldron

  • When Harry is buying his books at Flourish and Blotts, it mentions that he is being served by the manager, but when Harry is staring at the book Death Omens, it says that he is being served by the assistant of the store. Although, it is possible that the manager was simply the assistant to the shop owner.
  • The store clerk immediately moves to the cage with the "Monster Books of Monsters" inside them as soon as he sees Harry. However, as Care of Magical Creatures is only an elective for third year students, he had no reason to automatically assume that Harry needed that book without checking first.
    • It is possible that the clerk thought that Care of Magical Creatures was compulsory, or he had got a glimpse of Harry's booklist as he entered the shop.
  • Mrs Weasley complains that Fred and George have not been made prefects. However, as only one male Gryffindor prefect would have been chosen from their year, it would have been impossible for both of them to be prefects.
  • Mr Weasley says that Ron and Harry have ended up in the Forbidden Forest twice, but only Harry has ended up in the forest twice. Ron's first time into the forest was when he went with Harry to see Aragog in their second year, but in their first year, only Harry went into the forest for his detention; Ron was not there (he is in the film but not in the book). This error was corrected in later editions.
  • From Mr Weasley's conversation at the Leaky Cauldron, Sirius has known that Pettigrew was hiding at Hogwarts for several months. But in the Shrieking Shack in chapter 18, Sirius says that he first learned about it the night he escaped from Azkaban. However, it is possible that Sirius may have been referring to someone else, perhaps Harry or Voldemort. Sirius would know that Harry is at Hogwarts by the time that he is reported to start talking in his sleep and he might have heard about the Chamber of Secrets incident when Hagrid was imprisoned here.

Chapter 5: The Dementor

  • When Harry, Ron, and Hermione first find a carriage, and have stowed their luggage, they return to the platform to say goodbye to Mr and Mrs Weasley. Upon reentering the train, it is said that the three of them set off looking for an empty compartment and end up finding one at the very end of the train. Since the trio had already stowed their luggage earlier, there would be no need for them to go looking for an empty compartment. However, after Harry explains his situation with Sirius, it's revealed that Harry's Sneakoscope is in his trunk on the rack above them.
  • 1 September in 1993 was the night of a full moon. Therefore, Lupin should not have been on the train, considering how later in the book he is unable to teach for the three days around the full moon.

Chapter 6: Talons and Tea Leaves

  • Hermione's Time-Turner is a major secret that supposedly took a lot of persuasion to obtain. However, the reason it was necessary should not have been an out-of-place occurrence: any Gryffindor taking the Study of Ancient Runes would need to use one to attend their Friday Charms class that happens at the same time. Likewise, any Gryffindor who takes any combination of Divination, Muggle Studies, and Ancient Runes would require a Time-Turner since all of those classes occur at the same time on Wednesday mornings.
    • However, one solution is that Hermione's case was an unusual one: perhaps most students would be told that they could not take those classes together in one year, but she persisted in asking for them. Alternatively, the timetable may have been reshuffled in past years when students wished to take conflicting classes, or be put into classes with other houses to ensure attendance. A student taking all of the classes, however, would render these fixes moot and require alternative methods, such as the Time-Turner.
  • On page 101 of the US hardcover edition, Sybill Trelawney's name is misspelled as "Sibyll."
  • Trelawney tells Lavender, "Incidentally, that thing you are dreading- it will happen Friday the sixteenth of October." In 1993, when this happens, 16 October was a Saturday.
  • After Neville breaks his pink teacup, Trelawney asks Neville to get a blue one to replace it, as she likes the pink ones. She then proceeds to sweep up the shards of the first teacup with a feather duster and dust pan. It is unclear why she couldn't simply use a Reparo charm to fix the first cup.
    • It's possible that she was just being theatrical, which is something she's known for.

Chapter 8: Flight of the Fat Lady

  • On page 117 of the UK paperback edition, when Harry is talking to Lupin about the Boggart and he mentions Voldemort, it says "The only person Harry had ever heard say the name aloud (apart from himself) was Professor Dumbledore" But in the Philosopher's Stone, Hagrid says, "Nah - can't spell it. All right - Voldemort." Although, Harry may have excluded Hagrid as he does not use the name habitually. Hagrid also whispered it begrudgingly.

Chapter 9: Grim Defeat

  • During his substitution of the Defence Against the Dark Arts class, Snape says "That is the second time you have spoken out of turn, Miss Granger", but actually it is the third time she speaks out of turn. Although, Snape may have not counted the first time.

Chapter 10: The Marauder's Map

  • When describing the Fidelius Charm (with the scenario of Voldemort not knowing the secret), Flitwick says Voldemort wouldn't find the Potters even if he pressed his nose on the Potter cottage's sitting room window. As the cottage was under the Fidelius Charm (it is strongly implied to have been in Harry Potter and the Deathly Hallows), it would have been invisible to all but those who knew of the secret (as evidenced in Harry Potter and the Order of the Phoenix). Therefore, Voldemort wouldn't have been able to even see the sitting room window (or any other part of the cottage), let alone press his nose against it.
    • Flitwick could have meant that figuratively rather than literally.
    • Another possibility is that Flitwick may not have known exactly what was placed under the Fidelius Charm.
  • The name 'Marauder's Map' is grammatically incorrect, as it was presumably intended to be a reference to the group who called themselves the Marauders (who created it); the position of the apostrophe means there's only one Marauder. The gramatically correct name is therefore 'Marauders' Map', with the apostrophe coming after the letter 's', not before.
    • It is possible, though unlikely, that the name 'Marauder' was meant as a title for one who used the map.
    • It should also be noted that the group was only named the Marauders retroactively; the first on-page usage of the term doesn't come until Harry Potter and the Half-Blood Prince.

Chapter 11: The Firebolt

  • Remus Lupin tells Harry that the reason why the Dementors affect him so badly is because there are horrors in his past that the others don't have. However, given the extent of Voldemort's reign of terror during the First Wizarding War, it's highly likely that other students lost friends or relatives to his cause as well, so they should also be especially susceptible. In particular, Neville's parents were tortured into insanity, yet he's never mentioned to be as affected as Harry. It also seems somewhat inconsistent that the memory of his parents being killed is enough for him to be affected so much by the Dementors, but isn't enough for him to yet be able to see Thestrals.
    • One theory is that Harry's susceptibility is due to the piece of Voldemort's soul inside him in addition to his own soul making him an especially desirable target to the Dementors.
  • Given that Lupin had a transformation after Hallowe'en but before the following weekend, the full moon would have had to be sometime in the first week of November. Since a full moon occurs every month or so, the December and January full moons would also have occurred sometime around the first week of those months. Therefore, a full moon during the Christmas period is not possible. Yet, Dumbledore explains to Trelawney that Lupin's absence from the Christmas dinner is that he is not well again; implying either a transformation or post-transformation exhaustion, especially since Snape is mentioned as having brewed his potion for him.

Chapter 12: The Patronus

  • When Harry gets back into the Gryffindor common room with his Firebolt given back to him after being tested for jinxes, the common room admires the broom. An unidentified Gryffindor tells Harry, "Ravenclaw'll have no chance, they're all on Cleansweep Sevens!" However, later in the book, Oliver Wood tells Harry that Cho Chang, the Ravenclaw Seeker, rides a Comet 260.
    • It is possible that the unidentified Gryffindor who told Harry this only meant that most of the Ravenclaws ride Cleansweep Sevens. Or, it could be due to the fact that they didn't know the Ravenclaw team's line-up before the match, so they just generalised from what they had seen in previous games.

Chapter 14: Snape's Grudge

  • On page 285 of some versions of the US hardback edition, Snape's name is misspelled as "Snap".

Chapter 15: The Quidditch Final

  • When Hermione realised that she had missed her Cheering Charms lesson, it is unknown why she didn't simply use the Time Turner to go back and make it to the lesson. The Time Turner can go backwards in time up to five hours. Charms was immediately before lunch, and Harry & Ron confronted Hermione about the missed lesson immediately after lunch, so she was well within the 5 hour time limit.
    • Of course, according to the rules of time travel that will be established in this book's climax, everything that happens to the time traveller also happened in the original timeline. This means that, if Hermione had used the Time Turner in this instance, then from Harry and Ron's perspective, she would always have been at the Charms lesson, meaning that Harry and Ron would not have had any reason to confront her about missing the lesson, meaning she would not have had the reminder to use the Time Turner in the first place.
  • When Katie Bell is taking her second penalty shot, it says she put it past the Slytherin Seeker (Draco Malfoy), instead of the Keeper.
    • This error is corrected in later editions.

Chapter 16: Professor Trelawney's Prediction

  • This chapter takes place in June 1994. Harry Potter reads a note from Hagrid and says, 'Buckbeak's appeal — it's set for the sixth.' The night after the Hippogriff's appeal, Remus Lupin is forced into a werewolf form by the full moon, which means that this happened on the night of 6 June, 1994. The web page HP-Lexicon.org also backs this up. However, a brief look at lunar phase calendar sites such as 1994 and lunar phases in 1994 definitely shows 9 June, 1994, as a new-moon night, which means that a full moon could not possibly rise three days earlier.
    • In addition, during that Christmas's luncheon, Dumbledore, when asked by Harry about Lupin not lunching with them, explicitly states that 'the poor fellow is ill again', alluding to a possible full moon the night before. This is impossible, however, if June's full moon rose on the 6th, as a lunar cycle is 29.5 days long (requires verification).
      • While it is possible that like dates and days not matching up in the Harry Potter universe to the real world, J.K. Rowling slightly adjusted the moon's phases to fit the story, it is highly unlikely that she made the lunar cycle shorter, as this would have major consequences on the tides, with likely catastrophic results.
      • It is also possible that Lupin had caught the flu, or any other - curable - disease. Again, this is highly unlikely, as Dumbledore states that he is ill again, indicating a similar incident having happened before.
  • Before Harry and Hermione go back in time, it mentions that Buckbeak is tied to a tree. But when they go back in time, Buckbeak is tied to a fence. This error was fixed in later editions of the same book.

Chapter 17: Cat, Rat and Dog

  • It says "Ron crawled to the four-poster and collapsed onto it". But when Professor Lupin comes in, it says "his eyes flickered over Ron, lying on the floor". This could not be, as Ron should still be on the bed. Crookshanks was on the bed, and 'on the floor beside him.... was Ron' Ron moves from this position to 'protect' Harry. 'If you want to kill Harry, you'll have to kill us too' at this point he is standing, 'clinging painfully to Harry to stay upright'.
  • When Lupin tells Harry, Ron and Hermione that the Marauder's Map showed that someone was with them when they left Hagrid's hut, they argued that no one was. However, they knew that Scabbers was with them, and Harry already knows that the map shows animals, since among the characters he sees in the map when he first looks at it is Mrs Norris the cat.

Chapter 19: The Servant of Lord Voldemort

  • Snape says in the Shrieking Shack that Lupin had not taken his potion that night, but it is explained that one must drink the Wolfsbane Potion the week before transforming, not on the night itself.
    • It may be that the potion must be continually consumed before the full moon to be effective, rather than just once the week before.
  • During the climax, it is explained that it was Wormtail, not Sirius, who was the Potters' Secret Keeper and, therefore, traitor. In Chapter 21, Dumbledore confesses that he gave evidence that Sirius was the secret-keeper, and witnesses are only allowed to give evidence if it is something they have personal knowledge of. So he should have known from the beginning that it was Wormtail, not Sirius, who betrayed the Potters.
    • However, it is possible that a Secret Keeper is themself secret; with Sirius claiming the role as the most obvious choice and decoy from Pettigrew, only those told the secret would know who the Secret Keeper for the secret was. As it is, we don't know enough about how the spell works and its rules. It is likely that the evidence Dumbledore gave was his knowledge of the Potters' intent to use Sirius as Secret Keeper, and as the switch was kept secret, that would have been considered sufficient proof from his and others' points of view in the circumstances, as no-one had any reason to believe that Sirius was not in fact the Secret Keeper.
  • Sirius says that he persuaded James and Lily to use Peter as Secret Keeper instead of him, thinking that Voldemort would try to coerce the secret out of him. However, the whole point of the Fidelius Charm is that the Secret Keeper cannot be coerced into revealing their secret and can only do so willingly, and as he was so adamant that he would never have betrayed the Potters, his ruse was entirely unnecessary.
  • Sirius Black says that Voldemort has been in hiding for fifteen years. He's actually been in hiding for twelve years (almost thirteen at the time that he says it), about the same amount of time since Black was imprisoned. Voldemort went into hiding right after he was ripped from his body after failing to kill Harry. Of course, Black could just be rounding off to an approximated number (fifteen years), but this seems unlikely since he keeps talking about being in Azkaban for twelve years, being that the two time frames are almost exactly the same. Sirius also says to Pettigrew 'you haven't been hiding from me for twelve years, you've been hiding from Voldemort's old supporters'.
    • This is corrected in later editions.

Chapter 20: The Dementors' Kiss

  • When Lupin, Pettigrew and Ron are tied together, they are described as 'looking like contestants in a six-legged race', but it would actually be a four-legged race, as each pair of bound legs counts as one leg.
  • In the US paperback edition, when exiting the tunnel that lead out of the Whomping Willow, the group was in the following order: Crookshanks, Lupin, Pettigrew, Ron, Snape, Sirius, Harry, and Hermione. Later, when Hermione uses the Time-Turner, Harry and Hermione see themselves coming out in the order: Lupin, Ron, Pettigrew, Hermione, Snape, Harry, and Sirius.
    • This is corrected in later editions of the book.

Chapter 21: Hermione's Secret

  • On page 287 of the UK paperback edition, Dumbledore is speaking to Harry and Hermione and tells them, "There is not a shred of proof to support Black’s story, except your word – and the word of two thirteen-year-old wizards will not convince anybody," but Hermione's birthday is in September, so she's 14 years old at this point. However, this may not be considered a mistake, as it could be explained simply by Dumbledore not remembering Hermione's birthday.
  • Sirius was presumably sent to Azkaban without a trial on charges of being a Death Eater. However, in this chapter, while explaining the situation to Harry and Hermione, Dumbledore states that he gave evidence that Sirius was the Potters' Secret-Keeper. This would imply that there was at least some kind of trial. Sirius may not have been allowed to give evidence in his defence, but there would still have been a trial in the first instance, even if it was entirely ex parte.
    • A possible explanation is that Sirius's imprisonment (for the alleged murder of Peter Pettigrew and several Muggles) and the investigation of the Potters' deaths and the disappearance of Voldemort were two separate cases. In the first case, he was the main participant, with a number of testimonies confirming his guilt (mass murder and magic in front of Muggles). In the second case, Sirius was only one of the participants, and the purpose of this investigation was to find out the circumstances of the Potters' death, Voldemort's disappearance and to confirm that he had indeed disappeared. Dumbledore's testimony was given in connection with this case and was not related to the circumstances of Sirius's arrest and subsequent imprisonment in Azkaban.
  • When Harry and Hermione leave from the hospital wing using the Time-Turner, Dumbledore says it is ten minutes until midnight, but on the way back to the ward after they rescue Sirius, they hear Dumbledore say to the other versions of them that it is five minutes to midnight.
    • Corrected in later editions, making Dumbledore say "five minutes to midnight" the first time, instead of ten.

Chapter 22: Owl Post Again

  • In June, Fred and George Weasley find out they have scraped "a few O.W.L.s apiece." However, in subsequent books, it is firmly established that O.W.L. results are sent home by owl and are not received until July.
    • It is possible that those results were delayed due to the outbreak of the Second Wizarding War, although this is unlikely, as Professor McGonagall said that they would be receiving their results by owl.
    • Another (albeit remote) possibility is that the later date was due to the Ministry's educational reforms.
  • On page 311 of some editions, it said "Dumblefore" instead of "Dumbledore". This typographic error was rectified in later editions.

Harry Potter and the Goblet of Fire

  • In the early printings of the Scholastic edition, there are some books which were bound incorrectly, the spine and cover having been bound inverted. Upon opening, one notices that the text seems inverted, that the first page ones sees is really the last of the book.
  • 1 September 1994 was Sunday in the book but if 30 October 1994 was Friday, then 1 September would have to be Tuesday if you counted from that day to the 30 October. The book not only states 1 September was Sunday, but that the 2 September was Monday and that three days later on Thursday, Harry attended Defence Against the Dark Arts when in logically it would be Tuesday 1, Wednesday 2 and Saturday 5 September. The only way it could work is if both September and October were only exactly 4 weeks (or 28 days) long.

Chapter 1: The Riddle House

  • In the American version, there are repeated references to a planned murder, with lines such as "... one more death and our path to Harry Potter is clear" and "One more murder… my faithful servant at Hogwarts…" Yet, there is no indication that anyone else is murdered that was part of this plan. Bertha Jorkins was already dead, Frank Bryce was only a victim of circumstance, and Barty Crouch was originally kept alive and only killed because he had escaped and become a liability.
    • The British version specifically said curse; not murder. This was also corrected to "curse" in later printings of the American versions.

Chapter 2: The Scar

  • The narration mentions at one point that Harry "had only found out that Sirius was his godfather two months ago," when in fact it had been on the December Hogsmeade trip (in other words, eight months ago) when Harry overheard that Sirius was his godfather. It would be more accurate to say he "had only found out that Sirius was innocent two months ago."
    • Additionally, on the same page, Harry mentions that he had met Pettigrew "the previous year" rather than "two months ago.", though it is likely that referred to school year rather than calendar year (which would mean that the 1994–1995 school year was treated as the current year, even though it hadn't actually begun yet).
  • In the letter Harry writes to Sirius he mentions Dudley throwing his PlayStation out the window; however the PlayStation wasn't released until December 1994 in Japan and September 1995 in Europe.
    • Regarding that, J. K. Rowling has stated "I can’t work PlayStations. I’m no good at these things."
    • One in-universe explanation is that Dudley's parents may have bought one of the earlier available PlayStation prototypes designed for game designers, some of which were known to have been sold to private consumers. Alternatively, the PlayStation may have been released earlier in the Harry Potter universe, or Harry, due to his lack of interest in Muggle technology, might have confused the PlayStation with a similar console.

Chapter 3: The Invitation

  • Molly Weasley says in her letter to the Dursleys that Britain hasn't hosted the Quidditch World Cup for 30 years, but Quidditch Through the Ages states that the tournament is held every four years, and 30 isn't divisible by four.

Chapter 4: Back to the Burrow

  • Mr Weasley puts a pinch of Floo Powder into the fire for their group to return to the Burrow, but in Chamber of Secrets everyone has to use Floo Powder individually to travel.
  • Mr Weasley uses magic to deflect something that Vernon Dursley has thrown at him. In The Chamber of Secrets, Harry receives a warning from the Ministry of Magic for using magic in the presence of Muggles and also because he is underage and away from Hogwarts, even though it was Dobby who used magic, not Harry. We later learn that this is because the Ministry doesn't know when a specific wizard uses magic, but rather, where it is used. Since the Ministry knows Harry is the only wizard living in that general area, any magic performed is assumed to come from Harry. So why wouldn't Harry have received a letter after Mr Weasley performed magic in the Dursleys' home?
    • This might be because Mr Weasley notified the Ministry that he was going there, so they couldn't just assume it was Harry.
    • This might also be because the ministry cannot track magic done by wizards who are not underage.

Chapter 5: Weasley's Wizard Wheezes

  • While cooking, Mrs Weasley pours a creamy sauce from her wand. This breaks Gamp's Law of Elemental Transfiguration, which states that food cannot be created by magic. This could be explained as that Mrs Weasley is Summoning the sauce rather than conjuring it from nowhere.
  • After Hermione stops Ron from talking about Sirius Black in front of Ginny, it is stated that the only people who knew about his innocence are the trio and Albus Dumbledore, but Remus Lupin also knew and the trio knew that. It is also stated that Ron helped Sirius escape, even though he was in fact in the Hospital Wing recovering and was thus unable to accompany Harry and Hermione in the Rescue of Sirius Black and Buckbeak.

Chapter 6: The Portkey

Chapter 7: Bagman and Crouch

  • When Fred and George bet on the Quidditch match with Bagman, it says Fred put the paper with their wagers in his robes, but Fred was wearing Muggle clothing.
  • When the Weasleys, Hermione and Harry arrive at the camp site for the Quidditch match, they have to use a map to find where they set up their camps. Yet Percy, Bill, and Charlie are able to find them right away after Apparating in the woods. This is proved by Percy saying, "Just Apparated, Dad" as soon as they emerged from the woods. It seems impossible that the three could have found their camps that quick, unless Mr Weasley had sent a message to his sons while collecting wood for their fire.
    • However, it is said that their camping spot was located right next to the main path, so Percy, Bill and Charlie may just have got lucky.
    • It is also possible that the three eldest children did in fact go to find a map, and Percy was referring to them Apparating a short while ago.
    • Since Percy is a very proud person who has just left Hogwarts, he may be simply bragging about his ability to Apparate, while his younger siblings cannot.

Chapter 8: The Quidditch World Cup

  • In Quidditch Through the Ages, it is stated that the first-ever World Cup was in 1473, with a match being held every four years. Yet, the World Cup in 1994 is number 422. There cannot be 422 World Cups in 521 years with a four-year gap in between. (A 422nd Cup in 1994 would mean a first Cup in 306, while a first Cup in 1473 would mean a 422nd Cup in 3161). Only 130 four-year periods fit in 521 years.
    • Even if a sufficient amount of "ghost years" were to be added or a sufficient number of Cups removed, that would still make a perfect sequence of Cups every four years in this period impossible because 1473 is an odd number and 1994 is an even number. However, the 1877 World Cup was restaged the following year due to no one remembering it, which explains the discrepancy.
    • Possible explanations are that the period of years in between Quidditch matches in the past may have been different or irregular, that the years may have been counted differently, or that there were unofficial Quidditch events before 1473 that, although not exactly World Cups, were counted as so.

Chapter 10: Mayhem at the Ministry

  • In the American paperback edition on page 148, Harry asks Ron if he can dump his things upstairs in his room. It then states, "'What's up, Harry?' said Ron, the moment they had closed the door of the attic room behind them." In the Harry Potter and the Chamber of Secrets American paperback edition, on page 41, Ron says "... I'm right underneath the ghoul in the attic," referring to his room. Therefore the sentence in Goblet of Fire where he closes the attic door (to his room) does not make sense because that is where the ghoul resides.
    • Although with The Burrow being such a haphazard building, it is likely that it contains more than just one attic (an attic referring to a room beneath the eaves). Alternatively, attic rooms can have space between them and the roof, depending on the shape of the room. In such a case Ron's room may be called the attic room and still have attic space above it - as it would all still be beneath the eaves.
    • It is also possible that, due to the familiarity with the ghoul, the Weasleys managed to move it into a different room over the course of two school years. An example that supports this would be Ron's plan for the ghoul to take up residence in his room while he was away searching for Horcruxes with Harry and Hermione.

Chapter 12: The Triwizard Tournament

  • In the Scholastic Edition, in the 22nd line of the Sorting Hat's new song, Hufflepuff is spelt as "Hufflepujf."
    • This was fixed in later editions of the book.

Chapter 14: The Unforgivable Curses

  • Near the beginning of the chapter, Neville is assigned the task of disembowelling horned toads as punishment from Professor Snape. When Hermione teaches him the Scouring Charm to remove the filth from under his fingernails, they're referred to as "frog guts". However, the horned toad is actually a species of lizard, despite the name.
    • Since this was from Harry's point of view, however, he might not have known that fact and simply assumed the horned toad was a species of frog.
  • Barty Crouch Jnr says that the Ministry dictates that he is to teach only counter-curses to fourth-years, and not to actually show them any dark curses. However, towards the end of the book (in the penultimate chapter, The Parting Of The Ways), Cornelius Fudge says that he's always given Dumbledore free rein over what's taught at Hogwarts, with no interference from the Ministry.
    • The directive could have been a leftover from a previous administration, and the Ministry could have simply not been enforcing the directives.
    • Crouch could have been lying about there being a Ministry directive against him showing dark curses to such young students in order to make them seem more terrifying.

Chapter 15: Beauxbatons and Durmstrang

  • The notice that says classes will end a half hour early for the arrival of the Durmstrang and Beauxbatons students states that 30 October, 1994 is a Friday. However, it was really a Sunday.
  • When speculating how the visitors will be arriving, Ron suggests Apparition, saying that maybe under 17s in their countries are permitted to do it. However, as the Triwizard Tournament was only open to students aged 17 and above anyway, it wouldn't matter if they could. Also, Hermione reminds him that Apparition is impossible within the Hogwarts grounds, but there's still no reason why they couldn't Apparate to just outside the grounds and walk the rest of the way. Indeed, the trio do exactly that in the climax of the last book.

Chapter 16: The Goblet of Fire

  • Curiously, 1994 was the second year in a row in which Hallowe'en fell on a Saturday. In 1993, Professor Trelawney's prediction to Lavender Brown warned her that her worst fears would come true on Friday, 16 October. In 1994, 30 October was the date of the arrival of the Durmstrang and Beauxbatons students and was a Friday; the same day of the week it would have been in 1993 as the 30th fell exactly two weeks after the 16th. That is not possible because the same date does not fall on the same day of the week two years in a row.
  • When explaining the structure of the tournament, Dumbledore says that the winner will be the champion with the highest points total at the end of the three tasks. However, come the final task, the points have been converted into a staggered start order, and the winner is the first to touch the cup. Either Dumbledore was wrong, the plans changed, or this is a mistake.

Chapter 17: The Four Champions

  • Harry is said to be facing competitors who'd had three years more magical education than he had. But Cedric was only two full school years above Harry, so he'd only had two years' more magical education than Harry. However, Harry could have simply been referring to their ages and not their exact years of magical knowledge.
  • The book never says that all of Harry's competitors are three years above him: just that Harry would be up against those who are. Given that Cedric Diggory is only two years above Harry, "competitors who'd had three years' more magical education than he had" could be taken to mean Viktor Krum and Fleur Delacour but not Cedric Diggory.

Chapter 19: The Hungarian Horntail

  • As Hagrid takes Harry to see the dragons and he stops to pick up Madame Maxime, Harry wonders to himself "Had Hagrid wanted to show him Madame Maxime? He could see her any old time he wanted...she wasn't exactly hard to miss....". But this implies that Madame Maxime is easy to miss, the opposite of what is intended. It should say something to the effect of "she wasn't exactly easy to miss".

Chapter 20: The First Task

  • In the first task, nowhere has it been stated that one could not retrieve the Golden egg through the use of a Summoning Charm, but none of the champions even attempted this most simple system to do so. However, it is stated that the first task was designed to test the champions' daring and courage; thus, using a Summoning Charm would be too easy — almost to the point of cheating. It is possible that use of this spell would have resulted in a bottom score, or that there were enchantments on the eggs to prevent Summoning.

Chapter 23: The Yule Ball

  • Harry and the Weasleys abandon their snowball fight return to the castle at 7:00 pm, when it had become "difficult to aim", implicitly because it had gotten dark. However, in the Scottish Highlands, the sun sets around 3:30 pm on 25 December.[12] As such, it would have already been fairly dark when Hermione went up to the castle at 5:00 pm.
  • In the European and Canadian versions of the book, Snape shouts, "Ten points from Hufflepuff, Fawcett! And ten points from Ravenclaw too, Stebbins!" Really, Fawcett is in Ravenclaw, and Stebbins is in Hufflepuff.
    • It may, of course, be that Snape, angry as he was, mixed up the two students' affiliation to the houses. The American version corrects this error, but in a deleted scene from the film, included in the uncut DVD, Fawcett is again the Hufflepuff and Stebbins the Ravenclaw.

Chapter 25: The Egg and the Eye

  • After Harry is returning from figuring out the egg clue in the prefect's bathroom he gets stuck in the vanishing stair. This causes the egg to fall down the stairs making a racket and the Marauder’s Map to flutter away. Harry struggles to reach the map with his wand to clear the information. However, Harry just perfected the Accio summoning charm for the first task. He could have summoned the egg and the map and hid under the invisibility cloak until Filch and Snape gave up and left.

Chapter 26: The Second Task

  • In the Second Task, Viktor Krum transfigures his top half of his body into a shark's head to swim underwater without the need of air. However, in Quidditch Through the Ages it clearly states that when transfigured into an animal, the wizard loses all sense of human thought and becomes the animal until another wizard can transfigure them back. Krum who transfigured his head into a shark really should have attacked Hermione and not been able to do the task at all. Although, it is possible that due to the fact that Krum only partially transfigured himself, he might still have some control over his thoughts and actions.
    • Or, as ‘The Marauders’ (James Potter, Peter Pettigrew, Sirius Black and Remus Lupin) were able to be Animagi (but not Lupin as he was already a werewolf), Viktor Krum might be able to be ‘Part-Animagus’, but whether this is possible is unknown.

Chapter 27: Padfoot Returns

  • Snape says that the Gillyweed Harry used in the Second Task (which was given to him by Dobby) was stolen from his private stores. However, two chapters ago ("The Egg and the Eye"), he states that he locks his private stores with a charm that only a wizard can break. So it should have been impossible for Dobby to steal it.

Chapter 28: The Madness of Mr Crouch

  • Barty Crouch Snr mentions that his son got twelve O.W.L.s. Once again, this is inconsistent with the time-table clashes from Prisoner of Azkaban.
    • However, given Crouch Snr's damaged state of mind, he could have just been rambling insanely.
    • Another possibility is that it is not necessary to take a class in order to sit an O.W.L. This is logical since Remus Lupin mentions in Deathly Hallows that until Voldemort took over the Ministry, parents were allowed to educate their children at home, though virtually all British magical children attended Hogwarts. These students would presumably need the credentials given by an O.W.L. or an N.E.W.T. in order to obtain employment in many occupations. It is thus possible that a highly motivated student may be able to do "independent study" to achieve an O.W.L. or that a student was already so familiar with the Muggle world, for example, that they could easily pass an O.W.L. in Muggle Studies without attending classes.
    • It could also be explained as Barty Crouch Junior being provided with a Time-Turner, similar to how Hermione is provided with one in the previous book.
  • In some printings, the spell to revive Krum and Crouch from unconsciousness is ennervate. The correct spelling is rennervate, since ennervate would have the opposite effect (corrected in later editions).
  • On page 550, Cedric Diggory discusses with Harry what the third task of the Triwizard Tournament might be. He says Fleur keeps talking about underground tunnels and how she believes the champions will have to find treasure. Harry believes that that wouldn't be too bad because he could borrow a "niftier" from Hagrid. It appears to be a spelling mistake for the magical creature, the niffler, which the fourth years recently learned about in a Care of Magical Creatures lesson.
    • Harry may have just forgotten the correct name of the creature since there only was one lesson with nifflers up to this point. However, it seems unlikely because Harry is usually shown to retain information from most of his classes.
  • Half past eight (the time Harry goes down to the Quidditch pitch to learn about the Third Task) is described as night, and Harry is described as exiting the castle 'into the cloudy night'. However, sunset is a good deal later than that at that latitude and time of year (assuming Hogwarts is indeed near Dufftown, as claimed in Harry Potter and the Prisoner of Azkaban (film), sunset would have been around 9:45pm[13]). Therefore, it would still have been daylight when Harry went down to the Quidditch pitch.

Chapter 29: The Dream

  • Harry, Ron, and Hermione were supposed to call Sirius "Snuffles". Hermione calls Sirius "Snuffles" but she then calls him "Sirius" twice. It is likely, however, that Hermione simply made a mistake.
  • During the meeting between Fudge, Dumbledore, and Moody, Fudge is mistakenly referred to as both "Crouch" and also as his first name, "Cornelius."

Chapter 31: The Third Task

  • Voldemort's entire plan (to return in secret and build up his army in secret before revealing his return on his own terms) falls apart if the spectators can witness the third task. If everyone sees Harry and Cedric grabbing the Triwizard Cup and then disappearing, everyone would notice something is up. However, by all logical accounts, the Third Task should have been visible to spectators. The hedges in this chapter (which were set up in the Hogwarts Quidditch Pitch) were described as being 20 feet high, and in Chapter 2 of this book ("the Scar"), quidditch goal posts were said to be 50 feet high. It is highly unlikely that the stands would be placed below the goal posts, as this would make watching the match very inconvenient. Thus, those in the stands should have been seated 30 feet above the top of the hedge maze, giving them plenty of height with which to see into the maze. For that matter, making the inside of the maze invisible to spectators defeats the entire reason the Triwizard Tournament was brought back after more than a century: Having enough safeguards that the risk of death was minimal.
  • When Harry encounters the Limbo Mist, the sky is described as 'dark, star-spangled', which suggests that it was astronomical twilight if not full night, neither of which occur at that latitude and time of year.[14] Even if astronomical twilight did occur, it does not transition that quickly (when the task starts, the sky is described as 'deep, clear blue', with 'the first stars starting to appear', which suggests nautical twilight had just begun), and it is highly unlikely to have taken that long for Harry to encounter the mist. There may have been a few stars, but it seems unlikely that the sky was dark enough or that there were enough stars to reasonably describe the sky as 'star-spangled', and even describing the sky as 'dark' may be considered an exaggeration: during nautical twilight, it would have been semi-dark at most.
    • Nautical twilight would have begun at around 11:30pm (which seems rather late for even an event as major as a Triwizard Task). This also means that it's extremely likely that the Return of Lord Voldemort would have technically occurred on 25 June rather than 24 June, in the early hours.

Chapter 32: Flesh, Blood and Bone

  • In this and the next two chapters, Wormtail and Voldemort perform a wide assortment of dark magic - including all three Unforgiveable Curses - in rapid succession in close proximity to Harry, who still had the Trace on him. Bear in mind that, in 1992, when Dobby used a Hovering Charm, the Ministry noticed it immediately and, thinking it was Harry, had an owl sending a warning letter to Harry in only a few minutes. Also, remember that the Ministry knew that it was specifically a Hovering Charm (as opposed to simply "magic") being performed. By that logic, in this and the next two chapters, the Ministry should have instantly noticed the Unforgiveable Curses being performed in close proximity to an underaged wizard. Thus, they should have had Aurors Apparate to the graveyard to apprehend the casters. Never mind the potential for underaged magic; the fact that the Unforgiveable Curses were being used at all was grounds for Auror investigation! While the curses may not have been illegal if used on anyone other than a human being, that is not an excuse for the Ministry to not at least inquire into the matter, just in case.
    • If, as suggested with the mistake in Chapter 4, the Trace can only detect underage magic, the Ministry wouldn't be aware of the Curses being used, although it's not been established whether this is the case.

Chapter 34: Priori Incantatem

  • Toward the end of the book when Voldemort puts the Imperius Curse on Harry, the book says "for the third time in his life," but toward the middle of the book it states Harry had the Imperius Curse put on him four times by Moody (Crouch, Jnr.).
    • This, however, may have been a reference to the number of occasions and situations on which it was used rather than the exact number of times the curse was placed on him.
  • In what is now known as the "Wand Order Mistake," when Harry and Lord Voldemort's wands engage in Priori Incantatem while in the graveyard, James Potter exits the wand before Lily Potter. It has always been said that James died first as he was trying to give Lily and Harry time to flee, and since victims of Lord Voldemort were exiting the wand in reverse order of being killed, it was thought to have been a clue from J.K. Rowling.
    • Rowling later said that "late night writer's fatigue" was the reason, and the error has been fixed in later editions.
  • Prior to Bertha Jorkins coming out of Voldemort's wand there should have been indication of Voldemort making a Horcrux with her death, after she appears but before Lily appears there should also have been some indication of the methods Voldemort used to break her memory charm. It is of course possible he used another wand in both cases but unlikely he would have changed wands shortly after killing Bertha.

Chapter 35: Veritaserum

  • On page 594 in the first edition of the Canadian paperback and page 685 of the first edition American hardcover, when Dumbledore is questioning Barty Crouch, it says, "'How did your father subdue you?' said Dumbledore. 'The Imperius Curse,' said Moody." Crouch is mistakenly referred to as Moody in this sentence because it was after Barty Crouch had already returned to his original physical state (no longer an impersonation of Moody). Crouch had already been referred to by his real name earlier on that page, and the real Moody was lying stunned at the bottom of the trunk in his office.
  • Barty rigged the entire tournament to fool Harry into making contact with a Portkey, even though a Portkey can literally be anything. Had Crouch simply made a Portkey of his bedsheets or a schoolbook, Voldemort could have returned months sooner.
    • One possible explanation is that, much like apparition, portkeys do not work into or out of Hogwarts grounds unless the Headmaster explicitly authorises them. This would also avoid a potential plot hole: If the Third Task was not visible to spectators, how would the judges determine the winner if it was disputed who reached the cup first? Having the cup teleport the first one to touch it to the start of the maze is a foolproof way of knowing who touched it first. Thus, Voldemort had to wait patiently for Dumbledore to temporarily lower the anti-portkey defences in and around the Hogwarts Quidditch pitch, and only then could Crouch Jnr (disguised as Moody) volunteer to perform the task of turning it into a portkey.
    • Furthermore, as Sirius explains in the next book, Voldemort wanted to keep his return a secret (at least at first) and Harry's unexplained disappearance would make that harder to achieve. It is likely that Voldemort had been planning to transport Harry's dead body back to the maze via the portkey so as to pass his death off as an accident.

Harry Potter and the Order of the Phoenix

  • At least twice in the U.S. audiobook edition, Hermione pronounces the abbreviation for the Society for the Promotion of Elfish Welfare, S.P.E.W., as "spew" when speaking to Ron, despite her strong objections in the previous novel when Ron pronounced it this way, insisting on each letter being enunciated out loud.
  • In the book, classes begin the day after the Start-of-Term Feast. However, 1 September, 1995 was on a Friday, which would mean that classes started on the weekend, which is unlikely.
  • Sirius Black told Harry Potter that Bellatrix ran in the same crowd as Severus Snape while at Hogwarts, but her date of birth makes this impossible. Bellatrix would have attended Hogwarts from 1962 to 1969, or possibly 1963 to 1970, depending on which month in 1951 she was born in, whereas Snape began his schooling in 1971.
    • This may simply be an error since J. K. Rowling has admitted that maths is not her strong suit.
    • Another possible explanation could be that both Bellatrix and Snape went around with the same type of people, some of whom may have overlapped depending on age. For example, Lucius Malfoy was mentioned to be a prefect during Snape's Sorting in Deathly Hallows. However, this is rather unlikely as Bellatrix was heavily implied to be extremely active in Voldemort's war throughout the 1970s.
  • It is mentioned that Remus, rather than James, was the male Gryffindor prefect in Harry's father's year. However, Hagrid mentions in Philosopher's Stone that James and Lily were Head Boy and Girl at Hogwarts. Since it is implied that the Head Boy and Girl are chosen from the prefects, this does not work.
    • Although it is implied that the Head Boy and Girl are chosen from the prefects, it is never explicitly stated, so James could have been Head Boy without being a prefect.
    • If James had been Quidditch Captain, he could have become Head Boy through that, as Quidditch Captains have equal status with prefects.
    • Hagrid could simply have been mistaken in thinking that James had been Head Boy, but this is very unlikely as he knew him quite well due to both being members of the Order.
  • It states that after watching Ginny play it was Harry's first time watching Quidditch in the stands but Harry would have watched all the other matches that didn't involve Gryffindor (all matches since his first year at Hogwarts).
    • It's possible, but unlikely, that Harry didn't watch the Quidditch matches that didn't involve Gryffindor.

Chapter 2: A Peck of Owls

  • After Harry tells Uncle Vernon about Voldemort and Uncle Vernon tells Harry to get out, Dumbledore sends Petunia a Howler which says "Remember my last, Petunia" referring to the letter Dumbledore had left on the doorstep with baby Harry. Later, in Chapter 37, Dumbledore explains that Petunia "might need reminding of the pact she had sealed by taking [Harry]". However, in chapter 5 of the Chamber of Secrets, after Harry and Ron crash the Ford Anglia into the Whomping Willow, Dumbledore says he will "be writing to both [their] families tonight". This means that the Howler was referring to this letter about the flying car rather than the letter written by Dumbledore on the night of Lily and James' death as intended. Yet, if Dumbledore’s letter about the car was addressed to ‘The Dursleys’ (including Vernon), it is most likely that ‘Remember my last, Petunia’ was a reference to the last letter that Dumbledore sent exclusively to Petunia.
  • Mrs Figg tells Harry that she had stationed her cat, Mr Tibbles, to keep a watch on the Dursley house. However, in the first book, it gives a short list of Mrs Figg's cats, one of which is simply Tibbles, as opposed to Mr Tibbles.
    • A possible explanation is that Harry some or all of her cats' names mixed up, which is understandable as she has so many. Also, it's possible that they both refer to the same cat, only she calls it by slightly different names.
    • She could also be referring to the same cat, but changing whether or not to use the honorific. Many people switch between using 'Mr' or not before a name.

Chapter 3: The Advance Guard

  • When the Advance Guard arrives at 4 Privet Drive to take Harry to 12 Grimmauld Place, Harry is already in trouble for casting a Patronus Charm in the presence of a Muggle. Yet, Tonks casts several spells (Lumos, a packing spell, Scourgify and Locomotor Trunk) and Moody casts a Disillusionment Charm on Harry while they are still at 4 Privet Drive. Lupin had clearly stated that they were not using the Floo Network because they were being watched (by the Ministry), so of course the Ministry was not aware of any Wizards that are allowed to do magic inside Harry's house. If the Ministry can detect magic, and Harry is the only known wizard in Little Whinging, then he should have either had another owl sent from the Improper Use of Magic Office or the uses of those spells should have been brought up at some point during his trial.
    • Possible explanations include the fact that there were no Muggles present at the time, or that unlike Dobby, magic used by registered wizards does not activate the Trace. However, this is inconsistent with the seventh book, when Harry is told they had to escape using Polyjuice Potion and physical transport because using any magic at all around Harry would alert the Ministry to his presence. However that could be because of the rise of Voldemort at the time meaning heightened security around Harry - including making the Trace far more sensitive to spellcasting.

Chapter 6: The Noble and Most Ancient House of Black

  • A nest of dead puffskeins is discovered in 12 Grimmauld Place under a sofa. But according to some information, it's impossible, because the puffskeins are too big for going under a sofa and making nests.
    • This does, however, depend on the type of sofa - some do have larger gaps beneath them than others, especially older sofas, which Grimmauld Place may well have had. Additionally, the Puffskeins could have made a nest in the underside of the sofa which spilled out into the space beneath, like rats.
  • Sirius explains that he has been couped up in 12 Grimmauld Place since the start of the Second Wizarding War, since he is wanted by the Ministry and his dog form is now known to the Death Eaters, as Wormtail would most likely have told them about it. However, it is revealed in Deathly Hallows that Mad-Eye Moody has a large supply of Polyjuice Potion on permanent standby in case of emergencies (Hermione borrowed some of that potion for their upcoming Horcrux hunting mission, since Moody obviously wouldn't need it anymore). So it is unclear why Moody didn't simply lend some of his Polyjuice Potion to Sirius so he could exit the house every once in a while, and perhaps even go on missions for the Order, without anyone outside of the order recognising him. It is likely that Moody felt it necessary to keep his supplies with himself in case of an emergency, and Dumbledore felt it necessary to use this as an excuse to keep Sirius at the HQ to stay in contact with Harry to provide him with valuable information about his father and monitor and promote his rebellion against Umbridge.

Chapter 8: The Hearing

  • During Harry's hearing, Cornelius said that he blew up his aunt three years ago. However, the incident when Harry inflated Marjorie Dursley occurred almost exactly two years previously.
    • Although, this may be a mistake on Cornelius's part, and could show that he was not told accurate information, he had forgotten the date Harry blew up Aunt Marge, or that he was desperate enough to give away the wrong information; the second theory is most probable.
  • One of the charges against Harry is that of using magic in the presence of a Muggle, constituting an offence under the Statute of Secrecy, but as the Muggle in question (i.e. Dudley) already knows about the existence of the magical world, there's no point in charging Harry with this offence. However, it's possible that Fudge wanted to charge Harry with this anyway as part of his smear campaign against him, especially as he also brought up other incidents which weren't relevant to the trial.
  • When the Wizengamot is considering the verdict of Harry's trial, Madam Bones states 'Those in favour of clearing the witness of all charges?' As he has been accused of a crime and the subject of the trial, Harry should be referred to as 'the accused'. A witness attends court to give evidence only.

Chapter 9: The Woes of Mrs Weasley

  • Ron's prefect badge is described as scarlet and gold. Page 162 of the American paperback edition states, "A large P was superimposed on the Gryffindor lion. He had seen a badge just like this on Percy's chest on his very first day at Hogwarts." However, Percy's badge in Philosopher's Stone is described as silver with a P on it (later editions of the first book are fixed).
  • When Alastor Moody shows Harry the Order of the Phoenix photograph, he mentions that Caradoc Dearborn disappeared six months after the picture was taken, and implies that this was during the height of the First Wizarding War. However, he also mentions that Marlene McKinnon was killed two weeks after the picture was taken. Lily's Letter in Chapter Ten of the Deathly Hallows dates Marlene's death in late July or early August of 1981, putting Caradoc's disappearance around January 1982—three months after the end of the war.
    • However, it is possible that some Death Eaters continued to fight in Voldemort's name, similar to the group that tortured the Longbottoms.
  • In the American paperback edition, on page 161, when talking about the old Defence Against the Dark Arts teachers, Harry says, "One sacked, one dead, one's memory removed, and one locked in a trunk for nine months," referring to Lupin, Quirrell, Lockhart, and Moody respectively. However, according to the Prisoner of Azkaban American paperback edition, on page 423, Lupin did not get sacked — he resigned.
    • However, Harry could have interpreted Lupin's resignation as forced by Snape's revelation of his lycanthropy and therefore considered it the same as a sacking. Also, Fred does not mention either of his first two Defence Against the Dark Arts teachers, though it is possible that those two simply resigned and nothing particularly bad happened to them, thus no mention.
    • Lupin was not officially sacked, but there was pressure from the School Board for him to resign.
  • When asked to look into a desk in another room in Grimmauld Place, Mad-Eye Moody was able to determine it contained a Boggart. However, Remus Lupin established that nobody knows what a Boggart's true form is, as it always shapeshifts into the deepest fear of whomever sees it. It seems unlikely that the Boggart could have taken the form of Moody's greatest fear as he was not in the presence of the Boggart, so he must have seen it in its true form and known what it was.
    • It is possible the Boggart took the form of Moody's greatest fear and thus he was able to recognise it as a Boggart, but it has never been established that Boggarts can take on a subjective form if observed indirectly.
    • Maybe Professor Lupin didn't know that Moody has seen boggarts while he was teaching the lesson.
    • Because of this scene, it has also been said that Mad-Eye is the only person to have seen a Boggart in its true form.

Chapter 12: Professor Umbridge

  • Ron says "That's the worst Monday I've ever seen" in reference to his and Harry's schedule for the first day of classes. As school commences with the feast on 1 September, this first day of classes would fall on 2 September. However, at the end of Chapter 6, it is written that the night before Harry's trial is a Wednesday. Thus, Harry's trial, which takes place on 12 August, falls on a Thursday. So 2 September would actually have to be a Thursday, as well. (And in 1995, 12 August and 2 September were actually Saturdays.)
  • When Umbridge first puts Harry in detention she tells him to be in her office at 5:00. On the following day, when Harry goes to detention, the book says that he went to dinner before then, which means that dinner at Hogwarts starts at least at half past four, which is unlikely. However, dinner isn't always referred to as the 'last meal of the day' - in other books Harry, Ron and Hermione have headed to dinner as soon as afternoon lessons have finished. So it is conceivable that dinner at Hogwarts is served fairly early as lessons in UK secondary schools tend to finish between 3.30pm and 4pm. 'Dinner' does refer to the evening meal as the book refers to the midday meal as 'lunch'. Some British people call the lunchtime meal 'dinner' and the evening meal 'tea' but the books call the meals 'lunch' and 'dinner'.

Chapter 13: Detention with Dolores

  • Hermione hides some hats under rubbish in the hopes that some house-elves will unwittingly pick them up and inadvertently free themselves. However, this shouldn't work anyway. Even if house-elves can be freed simply by touching clothes of their own accord (rather than having clothes being given to them), Hermione has no power to free the Hogwarts house-elves, even if they wanted to be freed, as she is not their master, plus it's unlikely that elves can be freed this way, as this would make them unable to do laundry for their masters. If anyone can give clothes to a house-elf to free them regardless of whether they own the elf, then why did Harry need to resort to the "slimy sock and book" ruse at the end of Chamber of Secrets to get Dobby freed? Couldn't he have just given Dobby his own sock? And why didn't the Death Eaters give clothes to Kreacher to free him when he left Grimmauld Place just before Christmas?
    • It's possible that Hermione may not know enough about how elf ownership works to be aware that her ruse wouldn't work, although given the amount of research she did into the history of elf enslavement, there's a good chance that she would've picked it up.
    • Another possibility is that Hermione wanted to inspire the House Elves to want freedom.

Chapter 15: The Hogwarts High Inquisitor

  • In the UK audiobook version the line "Then you get "P" for "Poor" and "D" for "Dreadful"" is delivered in Hermione's voice, when it is obvious from context that Fred is the speaker.

Chapter 16: In The Hog's Head

  • Dennis Creevey shows up for the meeting in the Hog's Head. However, Dennis would only be a second year, and therefore unable to visit Hogsmeade.
    • He could, however, have sneaked out of the school with his brother, although what with Filch guarding the entrance and the Creeveys not having been notified of any secret passageways, this seems unlikely (unless they discovered one by chance).
      • However, Fred and George were both aware of whom Hermione was intending to recruit (having been recruited themselves) and could have shown him one of the secret passageways.

Chapter 18: Dumbledore's Army

  • Harry summons the escaping bullfrog with Accio in charms class. However, JK Rowling said "Accio only works on inanimate objects" after the Fantastic Beasts movie was released.
  • When Cho and Harry go to Hogsmeade together, she recalls their first match against each other "in the third year." As she is a year older than him it should have been "in your third year."
    • She may have been referring to the third year they had been on their house Quidditch teams, Gryffindor and Ravenclaw, respectfully.
  • February 14, 1996 was a Wednesday. There should not have been a Hogsmeade visit on Valentine's Day.

Chapter 19: The Lion and the Serpent

  • Harry refers to the Dark Marks on the arms of the Death Eaters as scars when they are actually brandings.

Chapter 22: St Mungo's Hospital for Magical Maladies and Injuries

  • In an error unique to the U.S. audiobook editions of Harry Potter and the Order of the Phoenix, when Harry first arrives at 12 Grimmauld Place following his vision of the attack on Arthur Weasley, the line "Back again, the blood-traitor brats! Is it true their father's dying?" is rendered in the loud, screechy voice of Sirius Black's mother. Based on context clues, however, particularly the fact that this line is immediately followed by Sirius shouting "Out!" and Kreacher shuffling out of the room, it seems clear that it was actually Kreacher that uttered the insults and not Mrs Black.
  • As Sirius is preparing to make breakfast, he calls out Kreacher's name twice with the express intent of summoning Kreacher to his side. In Half-Blood Prince, Chapter 19 ("Elf Tails"), as well as Deathly Hallows, Chapter 10 ("Kreacher's Tale"), whenever Harry calls out Kreacher's name, his house elf magic compels Kreacher to immediately Apparate to Harry's side, even if Kreacher is too far away to hear the call by normal means. Despite this being an established part of how house elf magic works, and one that Kreacher literally cannot ignore, Kreacher nonetheless does not answer Sirius's summons in this case.

Chapter 23: Christmas on the Closed Ward

  • Harry states that Dobby left the Malfoys to give him warnings two years previously, but it was in fact three years previously (two years previously would mean it happened in Harry Potter and the Prisoner of Azkaban).
  • Sirius could have easily just called Kreacher's name in order to force Kreacher to Apparate directly to his side (just like Harry would do in Half-Blood Prince and Deathly Hallows), so he could be questioned about his whereabouts. But Sirius never attempts this simple method of finding him or even considers it.
    • In fact, Sirius had already tried that method in the previous chapter, and it didn't work (see above for details). Which one is the bigger mistake, or if one actually justifies the other, is open to interpretation.

Chapter 26: Seen and Unforeseen

  • When Snape calls Voldemort "the Dark Lord", Harry makes an accusatory statement, claiming to have only heard the Death Eaters call him that, but in Prisoner of Azkaban, Professor Trelawney, who has never been suspected of being a Death Eater, called him that. Even earlier, in Chamber of Secrets, Ginny Weasley wrote a poem that referred to Voldemort as "the Dark Lord". Another year before that, in Philosopher's Stone, Ollivander also called him "the Dark Lord" as he talked about his past achievements.
    • However, Trelawney's use of the title "the Dark Lord" was used largely for poetic effect rather than out of loyalty.
    • It is possible that Harry forgot these examples due to his anger at Snape, or selectively ignored them in favour of accusing Snape of being a Death Eater.
  • Harry mentions that he gave the interview on the last Hogsmeade weekend. He did it on 14 February, which was a Wednesday in 1996.

Chapter 27: The Centaur and the Sneak

  • Why couldn't Hermione have used the Fidelius Charm to prevent Umbridge from finding out about Dumbledore's Army, with Harry as Secret Keeper?
    • In the Prisoner of Azkaban, Filius Flitwick describes the charm as "immensely complex", so it may have been beyond her abilities. However, she was able to put a Protean Charm on the coins that she gave to the group, which Terry Boot says is NEWT standard, so it's probably not implausible that she may be able to do a Fidelius Charm.

Chapter 28: Snape's Worst Memory

  • Draco Malfoy takes away points from Gryffindor and Hufflepuff when he catches Hermione saying what she really thinks of Umbridge. Then a conversation ensues in which Ernie Macmillan says that prefects can't take away points, even though Percy Weasley takes away points in Chapter 9 of the second book when he discovers Ron coming out of Moaning Myrtle's bathroom. In later editions this is fixed to say that prefects cannot take points away from other prefects, but this clarification is not reflected in the Jim Dale or Stephen Fry read audiobook editions of Book 5.
    • It may also be that Percy merely intended to report the trio's actions to someone who could take those points away, rather than doing it himself.
    • Another possible explanation may be that prefects can take points from students, but not from each other. Prefects have authority over the students, but they are equal to each other. When Draco took points from another prefect, he showed he is above this structure, he has the higher authority now. Limitations of prefects do not apply to members of Inquisitorial Squad.
  • After Harry has seen his father bully Snape in a memory, he remembers Professor McGonagall saying that James and Sirius were troublemakers at school but no more so than the Weasley twins. This is incorrect. She said in Prisoner of Azkaban that she had no memory of anyone else being so troublesome, and Hagrid said Fred and George could have given them a run for their money.
    • One possible explanation is that McGonagall's earlier statement was a hyperbole. Regardless, it was still not her who said that they were like Fred and George. (It actually just states in the book that Harry imagined them as precursors of Fred and George, so McGonagall didn't really imply it.) A large part of the community also refers to the twins as the successors of James and Sirius.
    • Another possible explanation is that both the pairs were the most known trouble-makers of different decades.

Chapter 29: Careers Advice

  • During Harry’s talk with Sirius and Lupin in the fireplace, Lupin says that James was 15 years old at the time of what Harry saw in Snape’s Pensieve. But this is a mistake as James and his friends were taking OWL Exams which happen in June in fifth year and James was born on March 27 1960, began attending Hogwarts on September 1 1971 and James’s fifth year was the 1975-1976, so James actually had to be 16 years old in the flashback Harry saw.

Chapter 30: Grawp

  • In the American hardcover edition, Harry and Hermione find seats in the topmost row at the Quidditch match, but when Hagrid comes to tell them about Grawp, he squeezes his way through the row behind them. If Harry and Hermione are in the topmost row, there cannot be a row behind them (corrected in later editions). But there could be a walkway behind the top row.

Chapter 31: O.W.L.s

  • It is stated that the practical Astronomy O.W.L. began at 11:00 pm, and Harry observed Venus one hour later (12:00 am). However, Venus can only be observed shortly before sunrise or shortly after sunset;[15] it can never be seen at midnight. Harry was also filling in his star chart with the stars in the constellation of Orion. However, Orion would have set before 11:00pm on that date.[16] Also, Hogwarts is somewhere in the Highlands of Scotland (according to the Prisoner of Azkaban film, it's near Dufftown in Moray); at that latitude, in the two months either side of the summer solstice, the sky never gets completely dark. Sunset in Dufftown on the day of the examination would be about 10pm, and it would still be civil twilight (only the very brightest stars and planets are visible during this phase[17]) at 11pm, the time the examination is supposed to start. Astronomical twilight (the point at which most stars become visible[18]) does not occur at all at that time of year; it never gets darker than nautical twilight (when only the brighter stars are visible[19]).[20] It therefore wouldn't have been dark enough to observe any but the brightest stars anyway.
    • The telescopes may be charmed to show every star regardless.
    • Harry could have mistaken Venus for a different celestial body.
  • During the Ordinary Wizarding Level examinations, Hannah Abbott was doing her Transfiguration practical at the same time as Harry Potter. This is odd since the examinations are done by surname, meaning that Hannah should have finished a while ago, unless she was a rather incompetent student, or unless she had a fit of anxiety in the middle of the examination and had to be calmed, which could take time, and then resume the exam when Harry started his. (It is implied that Hannah was given a Calming Draught).
    • The exams may have been done by first name.

Chapter 34: The Department of Mysteries

  • During the trip of Ministry of Magic with his friends, it was left out why there were no Order members there on watch duty, as in the beginning of the book, they mentioned about constantly being on watch duty, day and night.
    • It can however be assumed that, just as the defences on the Department of Mysteries seem to be impaired, the Death Eaters (who had already entered the Department) had removed the watching Order members when they broke in to wait for Harry.

Chapter 35: Beyond the Veil

  • In the UK paperback celebratory edition, the first line of the sentence which runs from page 710 to 711 is repeated, first on the bottom of page 710 and again at the top of page 711. The line reads, "Harry saw the look of mingled fear and surprise on his god-".

Chapter 36: The Only One He Ever Feared

  • Dumbledore sets up a portkey to teleport Harry directly into the Headmaster's otherwise impenetrable office. Earlier, he sets up a portkey in mere seconds to teleport Harry, Hermione, and the Weasleys from his office into 12 Grimmauld Place. This could arguably be considered a serious security risk to Hogwarts. While you cannot Apparate into or out of Hogwarts grounds, portkeys hardly seem like an inferior alternative, especially since, as Dumbledore demonstrates, they can be set up in mere seconds if you know exactly what you're doing. Couldn't Voldemort (during the First Wizarding War when he didn't need to worry about staying hidden) just portkey his way right next to Dumbledore's bed in the wee hours of the morning, and perform the killing curse on Dumbledore before he even wakes up?
    • One possible explanation is that, like the aforementioned mistake in Goblet of Fire, only the Headmaster can set up a portkey into or out of Hogwarts grounds. However, even that is not ideal in this case, because in the moment when he set up the Portkey to take Harry back to his office, he is not the headmaster anymore; Umbridge is.
      • Perhaps Umbridge, being the incompetent witch that she was, did not fully understand that the Hogwarts castle itself does not merely bend to the will of whoever the Ministry says is headmistress. Some type of ritual or spell must be performed in order for the castle and its various enchantments to recognise a person as headmistress and grant her the appropriate control over the castle's enchantments. Other teachers, such as McGonagall or Flitwick, may know how to properly install a new headmaster, but they willingly withheld this information from Umbridge. It is presumable that, as evidenced by its gatekeeping of the Headmaster's Office and a statement by Phineas Nigellus Black's portrait, the school itself still considered Dumbledore to be the true head; it therefore permitted him to make a portkey there despite the Ministry's decree to the contrary.
    • It is also possible that Dumbledore is capable of setting up a portkey directly into Hogwarts due to his mastery of the Elder Wand.

Harry Potter and the Half-Blood Prince

  • Harry's sixteenth birthday happens on 31 July, 1996. Looking at any full moon calendar, in that year the full moon was on 30 July. Remus Lupin was recovering from the after effects of his werewolf transformation and it is therefore difficult for him to go to birthday parties. It is said, though, that he was looking "gaunt and grim," so he might have transformed the night before. At Christmas, however, it is stated that Remus Lupin comes over to the Burrow and even uses Bill's bedroom. 24 December 1996 is the exact date of a full moon and, since Lupin was already living with the werewolves, there was little chance he could get the seven days worth of doses of Wolfsbane Potion required to make him harmless. Therefore, on that night he would have been a dangerous transformed werewolf.

Chapter 1: The Other Minister

  • Cornelius Fudge meets with the Muggle Prime Minister in the first chapter. At the time that this chapter is set, the real-life UK Prime Minister was John Major, but the book has some inconsistencies with this. Firstly, there are references to the election, but Major wasn't elected when he first assumed office and simply took over following Margaret Thatcher's resignation. Secondly, Fudge refers to the Prime Minister's predecessor as 'he'. Thirdly, he says that the predecessor tried to throw him out the window after the shock of learning about the existence of the Wizarding World from him, but Thatcher would've already heard about it from a previous Minister for Magic and therefore wouldn't have been shocked to meet Fudge, so probably wouldn't have tried to throw him out the window.
    • It is possible that J.K. Rowling was thinking of Tony Blair when writing this chapter, as he was PM at that time, in which case all these references would apply to him. He was elected when he came to power, his predecessor (i.e. Major) was male and Fudge would've been the first Minister for Magic that the predecessor met.
    • It is also possible that this Prime Minister is fictional and not intended to be any real-life figure.

Chapter 2: Spinner's End

  • Snape tells Bellatrix he had sixteen years worth of information on Dumbledore to give to Voldemort when Voldemort returned in Harry Potter and the Goblet of Fire. However, the time between Voldemort's original downfall and his return was less than fourteen years.

Chapter 5: An Excess of Phlegm

  • On page 101 of the earliest printings, and in the original audiobook editions of Harry Potter and the Half-Blood Prince, Ron mentions that Hermione got ten Outstandings and one Exceeds Expectations for Defence Against the Dark Arts, giving her a total of eleven O.W.L.s. However, since she dropped both Divination and Muggle Studies in her third year, she could not possibly have got eleven O.W.L.s since she was only doing ten subjects — Transfiguration, Charms, Herbology, Potions, Defence Against the Dark Arts, History of Magic, Astronomy, Care of Magical Creatures, Arithmancy, and Ancient Runes. This error was corrected in later editions, in which Ron instead says nine Outstandings and one Exceeds Expectations.
    • This so-called "error" did not even need to be corrected, as it could easily be explained that you are allowed to sit for an O.W.L. exam even without taking the corresponding class. For example, it is established in Deathly Hallows that attendance at Hogwarts has always technically been optional, and yet home-schooled students would likely still need the formal credentials provided by an O.W.L. Rather than correcting this "error" in later editions, it could simply have been said that Hermione volunteered for the Muggle Studies O.W.L. Since she was Muggle born, it would be a waste of time (not to mention rather condescending) to require her and other Muggle born witches and wizards to sit through two years worth of pointless classes just to be allowed to take the O.W.L. exam. This would explain her reading through the career leaflet on Muggle relations, which stated that the only qualification required was an O.W.L in Muggle Studies, and considering it as a career path despite having dropped the subject two years earlier.

Chapter 6: Draco's Detour

  • In the British audiobooks, when the Weasleys, Harry and Hermione are in "Weasley's Wizard Wheezes", the narrator says "patented daydream charms" in a voice that might indicate calling, but it is actually a sign on the product box and there are no quotation marks indicated in the print version of the book.

Chapter 7: The Slug Club

  • On page 126 in Chapter Seven on some American Editions it says Chapter One.
  • Malfoy does Petrificus Totalus on Harry and puts his invisibility cloak on him in the hopes that Harry will be sent back to London on the school train before anyone missed him. However, it was established as early as the first book that passengers on the train are typically instructed over the intercom system to leave their luggage and other belongings on board so that the Hogwarts house-elves can collect them and bring them to their respective dormitories. So by all accounts, Harry should have been discovered long before the train began its return trip.
    • It's possible that Malfoy may not have been aware about this fact, though this is unlikely as he ought to be from previous years.
    • Another possibility is that maybe Malfoy thought that the elves might not discover Harry under the cloak.

Chapter 8: Snape Victorious

  • It's stated that Harry has never appreciated the distance between Hogsmeade station and Hogwarts due to having always covered it by carriage. However, he only did so from his third year onwards, because in his first year he sailed across the lake and in his second he flew with Ron in the Ford Anglia.
  • When Harry gets off the train and encounters Snape, Snape tries to take off 70 house points and tells Harry that he has set a record for getting negative house points at the beginning of the school year. However, when Snape tries to take away 10 house points from Gryffindor at the end of Order of the Phoenix, Professor McGonagall says that there isn't anymore house points to take away from Gryffindor, and so she must add some first before any can be taken away.
    • It's possible that Snape may have just been trying to be mean and make Harry worried about giving Gryffindor negative house points.

Chapter 9: The Half-Blood Prince

  • At the start of term feast, Dumbledore tells Quidditch hopefuls to put their names down for selection. For the Gryffindor House, at least, there had never been trials before. Katie Bell also warns Harry against just "picking the old faces," but this had automatically been the case for the five years preceding Harry's sixth year. It is likely Wood was happy with the team for three years, and there was no reason to hold a trial with no spots becoming vacant up until he left. There was no need to hold trials in Harry's fourth year. Angelina Johnson held trials in Harry's fifth year, but only for the parts that needed to be filled in; this could mean that Angelina was happy with the remaining players on the team.
    • This may also be a sign of Harry simply bowing to pressure since he could have chosen to allow those that were already on the team to continue playing but instead chose to take Katie's advice.
    • It is also possible that a new team is chosen only if there's a new captain.
    • Lastly, it could be that Katie was referring to the bad players from the previous year, and simply wanted to replace the players who had weighed down the team.
  • Harry is made Gryffindor Quidditch Captain in his 6th year, however Katie Bell who is attending her 7th and final year of Hogwarts is not made Captain. The mistake is that since Angelina took over for Wood when he left school, it is assumed that the next highest grade player would be chosen as a new Captain for the Team. Following that logic, Katie should have been picked instead of Harry, but she did not even consider herself becoming Captain when she says, " "I thought you'd get that, well done," she called over, pointing at the Captain's badge on Harry's chest. "
    • While it may be assumed that the most senior player is chosen as Captain, it's never explicitly stated.
  • In the sixth year's first Potions lesson with Slughorn, where he offers Felix Felicis as a prize, he states that the vial contains "enough for twelve hours' luck." However, when Harry is considering taking it to get the memory from Slughorn, he tells Ron and Hermione that he would only need to take a bit of the potion, "not twenty-four hours' worth." This error, found only in the American version of the book, is corrected in later editions.
  • It says, "Draco had a look on his face similar to the time Hermione had punched him", but in the novel Harry Potter and the Prisoner of Azkaban, Hermione slaps him. This is true in the film adaptation, though, so J.K. Rowling may have mixed up the events of the films and the books.

Chapter 10: The House of Gaunt

  • On page 196 (American Edition), Harry is mentioned going to Dumbledore's office for his private lesson on the 7th floor of Hogwarts. When it is shown that Dumbledore's office is on the 3rd floor of Hogwarts in the 2nd book (Chamber of Secrets/Chapter 12: The Polyjuice Potion), when Harry is taken there by Professor McGonagall.

Chapter 11: Hermione's Helping Hand

  • First-year students show up for the Gryffindor Quidditch team tryouts, despite the fact that, according to Hogwarts rules, first-years are not allowed to try out for house teams.
    • However, as many other non-Quidditch playing students as well as students from other houses attended the tryouts to be near Harry, it is possible that these first-years followed their example. It is also likely that Harry chose to allow first-years to participate to gauge if they had special talent regardless of age, as Harry himself was exempted from the first-year rule and allowed to join the team due to his exceptional talents as Seeker.

Chapter 13: The Secret Riddle

  • Dumbledore visits Tom Riddle in the orphanage to offer him a place at Hogwarts, but Armando Dippet was headmaster at that time, so he should've been the one visiting the orphanage, rather than Dumbledore.
    • If Dumbledore was then deputy headmaster, it is possible that Dippet may have delegated the task to Dumbledore due to being unable to do it himself for whatever reason.
  • It says, "... Dumbledore entered the room... It was a small bare room with nothing in it except an old wardrobe and an iron bedstead." A couple paragraphs later, "Dumbledore drew up the hard wooden chair beside Riddle, so that the pair of them looked rather like a hospital patient and visitor."
    • This may have been a pun, since with Dumbledore especially, the term "draw up a chair" is used in a literal sense several times when Dumbledore magically conjures a chair by drawing it. This may have been a covert way of implying this, especially considering Riddle may have missed this action by Dumbledore.

Chapter 15: The Unbreakable Vow

  • Ron states that Fred and George almost goaded him into making an Unbreakable Vow when he was around five. This would mean that Fred and George were around 7 or 8 when this happened. However, in Chapter 2 of this book, it is revealed that this spell requires a wand, even when performed by the exceptionally skilled Bellatrix Lestrange. Fred and George should not have been eligible to have wands until they were 11 years old.
    • It is possible that they might've borrowed a parent's wand.

Chapter 16: A Very Frosty Christmas

  • On page 342 of the American version, there is a punctuation error when Molly Weasley says "Have a little purkey, or some tooding...I mean-" to Rufus Scrimgeour. There are no quotation marks in front of the "have" in the statement. This mistake is corrected in later printings.

Chapter 19: Elf Tails

  • On page 415 of the American edition, it says "...McLaggen took a ferocious swipe at the Bludger and missed it." In the original edition "missed" was mistakenly printed as "mishit". This was corrected in later editions.

Chapter 22: After the Burial

  • Harry sees Dean, Neville, and Seamus in the common room just before he takes Felix Felicis. But as he is leaving Gryffindor tower a few minutes later, Dean and Ginny are entering through the portrait hole.

Chapter 23: Horcruxes

  • Dumbledore says that Voldemort didn't want to wear Gaunt's ring after turning it into a Horcrux, but Harry saw Voldemort wear the ring in Slughorn's memory. Pursuant to Morfin's memory and Dumbledore's explanation, the Riddles were killed right after Voldemort met with Morfin and stole the ring. There would not have been enough time for Voldemort to steal the ring, return to Hogwarts, and then kill the Riddles and make the ring into a Horcrux.
    • However, it is possible that a Horcrux does not need to be made immediately following a person's death; for instance, Riddle could have killed his parents, stolen the ring, worn the ring at school and then, sometime later, used the damage inflicted on his soul upon murdering his parents to make the ring into a Horcrux, at which point he would have stopped wearing it. This would make sense, as Riddle didn't even know whether it was possible to create more than one Horcrux until this meeting and had already made the diary into one at this point.

Chapter 27: The Lightning-Struck Tower

  • When Draco tells Dumbledore about the enchanted coins that he used to communicate with Madam Rosmerta, the latter remarks about Dumbledore's Army using the same method. It's unclear how he would've known this, as Marietta is implied to have only told Umbridge that there was a meeting in the Room of Requirement with no further details.

Chapter 30: The White Tomb

  • Rufus Scrimgeour tells Harry that the Ministry believes he was with Dumbledore when he left the school since there were two brooms on the Astronomy Tower and that "someone Stupefied a Death Eater on top of the Tower after Dumbledore died." However, while Harry did incapacitate said Death Eater, Harry used Petrificus Totalus (the Full Body-Bind Curse) and not Stupefy (the Stunning Spell).

Harry Potter and the Deathly Hallows

Chapter 1: The Dark Lord Ascending

  • With the death of Albus Dumbledore, Severus Snape should have become a secret-keeper for the location of 12 Grimmauld Place, and thus could have revealed that information to Voldemort. Perhaps Moody's Tongue-Tying Curse was keeping him from disclosing the information, but if that were the case, the casters of the Fidelius Charm could have used the curse more often to prevent the sort of treachery that led to Lily and James Potters' deaths.
    • More likely he did become a secret-keeper, but hid this fact from the Death Eaters due to his true loyalty secretly being to Dumbledore, and since Voldemort did not know Dumbledore was the Secret Keeper, he wouldn't suspect Snape. It is also possible that Snape indeed told Voldemort, but the latter believed it was worthless to go there since the Order would have changed their headquarters.

Chapter 2: In Memoriam

  • It is said that Harry never learned how to repair wounds, but he did learn at least one spell for such a purpose: Episkey, a spell which he even used at least once during Quidditch practice during Half-Blood Prince, Chapter 14 ("Felix Felicis"). Perhaps episkey is only for minor lacerations, but Harry moves past this cut on his hand just by running some water over it and administering some Muggle first aid. If it wasn't a minor laceration, he has no business ignoring it and should have called for an ambulance, and there is no indication that his otherwise untreated cut had impeded his wand hand for the rest of the book, or even that other characters even noticed it.
  • It is said that Harry cannot use magic due to not coming of age for another four days. In chapter six, days have passed since the Battle over Little Whinging, but Harry states the Trace will break in four days.

Chapter 4: The Seven Potters

  • As Harry is awaiting the Order, he reminisces about the few times as a boy he was left alone at Privet Drive as the Dursleys went out for fun, mentioning how he would often play on Dudley's computer and sneak tasty treats from the fridge. However, in Harry Potter and the Philosopher's Stone, it is made clear that the Dursleys would never do anything of the sort, fearful that they would come back to find the house in ruins, instead opting to leave him with a babysitter (preferably Arabella Figg).
    • It is possible that he was referring to summer holidays after he had found out he was a wizard, such as in the summer of 1994, when the Dursleys had significantly let up on their abuse of Harry out of fear of retaliation from Sirius. However, by that point, he would likely have had no interest in Muggle entertainment such as television or video games.
  • Right before the Battle of the Seven Potters, Moody explains that the Ministry has restricted the use of Portkeys, Floo Network, or Apparition within the Dursley's house, which is why they had to resort to the elaborate "Seven Potters" ruse to get Harry to safety. However, this restriction only applied to the Dursley's home. They could have just placed a Portkey one foot outside the Dursley's lawn and had Harry jump to touch it, or have Harry grab Moody's arm and jump off the lawn at the count of three before undergoing side-along Apparition. Even if they absolutely had to use the "Seven Potters" ruse initially, the fourteen of them could have just disApparated - side-along or otherwise - the minute they took flight.
    • They were still unable to use magic around Harry due to the Trace. However, as soon as the Death Eaters attacked, magic was being used all around Harry anyway, so why bother with the technicalities at that point?
  • Couldn't Harry and Moody have simply walked together under the Invisibility Cloak a safe distance away from the Dursley's home (such as Mrs Figg's front yard) before undergoing side-along apparition?
    • There are ways of detecting people under an Invisibility Cloak, as evidenced by the Marauder's Map. However, this begs the question: why aren't such methods used more often, such as when the trio appeared at the Hogs Head prior to the Battle of Hogwarts?

Chapter 5: Fallen Warrior

  • Harry says 'What d'you mean? Isn't anyone else back?' but the first apostrophe is missing.

Chapter 6: The Ghoul In Pyjamas

  • On page 78, Sept 2014 Edition. When Ron is explaining to Harry his plan to use the ghoul as a decoy Ron "with spattergroit", Rowling writes 'Harry merely looked his confusion'. This is presumably a typo / grammatical error as the sentence doesn't make sense. The most likely intended sentence is 'Harry merely looked with confusion'.

Chapter 13: The Muggle-Born Registration Commission

  • Harry and Hermione call each other by their real names while freeing the Muggle-borns awaiting trial, rather than those of the people they are impersonating, which is sure to blow their cover.
    • It is possible, given that they were freeing Muggle-borns, that they felt their cover had already been blown, and therefore didn't worry about it. However, this is unlikely, as Harry resumed impersonating Runcorn when he was challenged over freeing the Muggle-borns.
    • Another possibility is that they didn't think it necessary to maintain their cover whilst in the presence of only the Muggle-borns, as it would have been fairly obvious they they were not who they appeared to be anyway.
    • It is also possible that they panicked and momentarily forgot that they were under cover.

Chapter 14: The Thief

  • Hermione is afraid to return to 12 Grimmauld Place for fear that she had inadvertently given the location to Yaxley. Harry theorises that Yaxley is also bringing other Death Eaters into the place. However, Yaxley should have been unable to do so, as only a secret-keeper can reveal a location hidden by the Fidelius Charm, and Yaxley would not have become a secret-keeper simply by learning a hidden location from another secret-keeper. He would only become a secret-keeper if the secret-keeper who reveals the secret to him (in this case, Hermione) actually dies.
    • One possible explanation is that the Death Eaters may have deduced that, because Hermione was able to give the location to Yaxley, either she was the original secret-keeper (which is highly unlikely) or she is a second-generation secret-keeper, meaning the original secret-keeper was dead. Even if they didn't know that the original secret-keeper was Dumbledore, the fact that the original secret-keeper (whoever they may be) is dead necessarily means that Snape is now a secret-keeper as well, meaning Voldemort might have likely asked Snape to divulge the information, and Snape complied in order to maintain his cover.
  • It is also a part of Fidelius Charm lore that a secret-keeper cannot be coerced into revealing the protected information; it must be divulged willingly. Therefore, Yaxley should not have been able to learn the secret simply by grabbing onto Hermione and not letting go, as this would not have been voluntary on Hermione's part.
    • However, this could just be Harry and Hermione's speculation based on their limited knowledge on the Fidelius Charm.

Chapter 15: The Goblin's Revenge

  • Ted Tonks uses Summoning Charm on a fish in the river by sayin 'Accio salmon' and it works. However it is said in the Book of Spells and Rowling's Official Site that 'Accio only works for inanimate objects'. A possible explanation is that the Summoning Charm merely causes irreparable harm to living things, such as turning their organs inside out, and since Ted and his friends were just planning on eating the salmon anyway, this wasn't a concern for him.
    • In chapter 18 of Order of the Phoenix, Harry summons a bullfrog during a charms lesson, which proceeds to gloomily come back to him. Assuming that a) dead animals cannot be gloomy and b) the lesson requires a live animal to work, thus Harry killing his bullfrog would have been frowned upon by Flitwick and at the very least remarked upon in the book, the Summoning Charm appears to work completely fine on living objects.
    • Why didn't Harry or Hermione or Ron think of using a summoning charm for anything they wanted to eat?

Chapter 20: Xenophilius Lovegood

  • Ron explains that Voldemort had placed a Taboo on his name so that if anyone said it he would be able to find that person, and explains that was how the Death Eaters had found them on Tottenham Court Road — Hermione used the name once, while they were sitting in the cafe. However, the trio used Voldemort's name several times while they stayed at 12 Grimmauld Place, and the Death Eaters did not manage to find them there until Hermione accidentally brought one back with them, after Disapparating from the Ministry of Magic, although one or two strangers did appear near Grimmauld Place before with a dozen on September 1st. The charms placed on 12 Grimmauld Place which make the location impossible to enter unless invited but the jinx placed on Voldemort's name is specifically said to "break protective enchantments." However, it is highly likely that it may not be able to break the Fidelius Charm, which is notoriously strong.
  • When Harry, Ron, and Hermione are at the front door of Lovegood House, Hermione says to Harry, "You better take off the Invisibility Cloak, Harry, it's you Mr Lovegood wants to help," and he handed her his Cloak to place in the beaded bag, but after the Death Eaters arrive Hermione says, "Harry give me the Invisibility Cloak, Ron, you're going to put it on."

Chapter 23: Malfoy Manor

  • Narcissa says that Draco "is home for his Easter holidays." In the next chapter, the sun is described as rising at Shell Cottage in Cornwall, but shortly after this, Harry sees into Voldemort's mind at Hogsmeade, where it is "still dark, because it was so much farther north." However (in the absence of a significant longitudinal difference, as in this case), this sort of thing is only true between the Autumnal and Vernal Equinoxes; Easter occurs after the Vernal Equinox[21] (e.g. on 12 April in 1998), in the other half of the year when sunrise is earlier the further north one goes, thus it should not have been dark at Hogwarts when Harry saw into Voldemort's mind.

Chapter 25: Shell Cottage

  • Lupin says that Bill is the Cottage's Secret Keeper, yet Ron was able to tell Dobby about where the cottage was when escaping from Malfoy Manor. However, this is most likely because Ron was aware of the cottage's existence prior to the Fidelius Charm being placed on it, and thus was free to divulge the information on its whereabouts. However according to this logic, Bellatrix Lestrange should be able to tell Voldemort about 12 Grimmauld Place.
    • However, it is possible that the Fidelius Charm does not work on elves, since it is shown multiple times in the books that elf magic works differently with wizard magic.
    • It is also possible that Dobby merely Apparated right outside Shell Cottage for the Secret Keeper, Bill Weasley to lead them in.

Chapter 27: The Final Hiding Place

  • Harry drips dittany through the singed hole in his jeans to the angry burn beneath, but he has just got changed, so he shouldn't be wearing his singed jeans anymore. Not much later in this chapter, Harry returns from an excursion into Voldemort's mind, and is "vaguely surprised" that he is "still wet to his skin", which he should not be since he had got changed into dry robes earlier. Harry may have been so affected by this excursion that he woke up in a cold sweat, but this is unlikely, since Harry has had a lot of experience seeing Voldemort's thoughts by this point, and because the statement implies that Harry's clothing is still soaked.

Chapter 33: The Prince's Tale

  • When Harry is viewing Snape's memories, he witnesses a scene on Platform 9¾ between his mother and Aunt Petunia, in which Petunia tugs her hand out of Lily's grasp. Her hand is then back in Lily's, and she tugs it out again.
    • Lily may have grabbed her hand again against her will.
  • Dumbledore asks Snape to cast a Confundus Charm on Mundungus Fletcher, but since Voldemort took over the Ministry after the chase, Snape shouldn't have been able to enter Hogwarts and go to the Headmaster's Office. Unless Dumbledore showed him a way to enter unnoticed, had allowed him access, or something similar.
    • It is also possible he used the Vanishing Cabinet in Borgin & Burkes to enter the Room of Requirement at night and thus sneak to the Headmaster's Office, or used the same passage through the Room of Requirement that the DA later used.
    • Alternatively, he might have entered at day time and used a Disillusionment Charm in order to render himself almost invisible and spy on his former colleagues in order to find out what the password for the office is.

Chapter 36: The Flaw in the Plan

  • Harry sees Charlie Weasley overtaking Horace Slughorn and in the next page Voldemort is seen duelling McGonagall, Slughorn, and Kingsley; however, Slughorn could have caught up again, possibly due to Charlie being distracted by something else.

Harry Potter and the Cursed Child

Part 1

Act 1

  • Scene One and Scene Two take place in the Epilogue: Nineteen Years Later of Harry Potter and the Deathly Hallows. However, there are a few modifications. In Harry Potter and the Cursed Child (Special Rehearsal Edition), the whole Potter family run into the barrier together. In the book, James leaves before the rest of his family. Some lines in the book are not said by the same characters. In the play it's Harry who says "James, give it a rest" while in the book it's Ginny.
    • Albus explains why he doesn't want to be in Slytherin, stating "Slytherin is the House of the snake, of Dark Magic... it’s not a House of brave wizards".

Act 2

  • When Albus sees Harry's name come out of the Goblet of Fire, there is cheering (albeit less enthusiastic cheering than for Cedric). This contradicts the actual events of Goblet of Fire, where - at the beginning of Chapter 17 (the Four Champions), in the first sentence of the second paragraph - it is stated in no uncertain terms that "There was no applause" for Harry.
  • When Eloise Mintumble time-travelled and changed things, it was noticed by other witches and wizards from the original timeline who went to retrieve her without seemingly time-travelling themselves. When Albus Potter and Scorpius Malfoy time-travelled and changed things, no one from the original timeline knew they could retrieve them. They never mention being able to retrieve them in the same way Eloise was retrieved.
  • When Eloise was retrieved, her body aged the five centuries it had to travel through, and it created paradoxes such as Tuesday lasting two and a half days and Thursday going by in only four hours. When Albus and Scorpius time-travel, the only real consequences was that things had changed and Albus' arm being injured as if it broke twenty years ago and 'allowed to set in the 'most contrary of directions'. There are no paradoxes.

Part 2

Act 4

  • In the play, Polyjuice Potion seems faster to make. In Act 4, Scene 10, Albus proposes that they use this potion to turn into Voldemort because he thinks Bathilda Bagshot may have all the ingredients, and Ron only contradicts him with the argument that they don’t have a bit of Voldemort, just like as though the one month of preparation was not an issue when they only have a few hours ahead of them.
    • Both may have assumed that either they could use the Turner again to give themselves time to make the potion or Bathilda would have a potion ready for their use.
  • Harry only had the ability to speak Parseltongue because he was a Horcrux. He never knew how to speak it himself. It only happened because he had a piece of Voldemort's soul residing in him. Rowling stated this to be correct in an interview when she confirmed that Harry "lost the ability and was very glad" when Voldemort destroyed that part of his soul. However, in the play, he speaks it anyway as though he had never lost the ability.

Rowling's Companion Writings

  • Quidditch Through the Ages
    • A discrepancy is that although Harry had the book in his first year (1991-1992), there is an event listed that occurred in 1994. It is, however, possible, that the "real" edition was updated. (Although this is unlikely, as the most recent model of Nimbus broom mentioned is the Nimbus 1700 and the Nimbus 2000 and 2001 were released in 1991 and 1992 respectively.)
    • In chapter 1, Gertie Keddle's diary is described as being written in 'badly spelled' Saxon, but there was no standard way to spell words in her time anyway.
    • In chapter 4, a witch named Modesty Rabnott summons a Golden Snidget by using Summoning Charm, but living creatures can't be summoned by this spell.
    • In chapter 7, it says that the first Quidditch World Cup was held in 1473.[22] If the championship is held every four years, this conflicts with the statement in Goblet of Fire that the 1994 championship was the 422nd. If Quidditch Through the Ages is right, the 422nd Quidditch World Cup was actually held in 3161, but if Goblet of Fire is right, the first World Cup was actually held in 306.
    • In chapter 8, it's stated that Quidditch has never achieved widespread popularity in Asia due to broomsticks being rare in countries where carpets are still the main mode of transport. However, Pottermore states that Syria won the World Cup in 1974, which seems unlikely as Middle Eastern countries in particular are said to be especially prevalent in the flying carpet trade.
    • The book says that the European Cup takes place every three years, but it's mentioned to have been held in 1931 and 1956. This is a gap of 25 years, which isn't divisible by 3. It is possible that one or more editions between those dates may have been delayed due to the Global wizarding war.
  • Fantastic Beasts and Where to Find Them (companion book)
    • In the 'About the Author' section, it is stated that Newt Scamander graduated from Hogwarts, however in the film and screenplay Percival Graves says that he was thrown out for endangering human life with a beast.

Notes and references

  1. Differences between editions of the books
  2. Harry Potter and the Half-Blood Prince, Chapter 25 (The Seer Overheard)
  3. Harry Potter and the Chamber of Secrets, Chapter 18 (Dobby's Reward)
  4. Harry Potter and the Prisoner of Azkaban, Chapter 22 (Owl Post Again)
  5. 5.0 5.1 Harry Potter and the Half-Blood Prince, Chapter 30 (The White Tomb)
  6. Harry Potter and the Deathly Hallows, Chapter 3 (The Dursleys Departing)
  7. Harry Potter and the Deathly Hallows, Chapter 6 (The Ghoul in Pyjamas)
  8. 8.0 8.1 Harry Potter and the Deathly Hallows, Chapter 7 (The Will of Albus Dumbledore)
  9. Harry Potter and the Half-Blood Prince, Chapter 3 (Will and Won't)
  10. Harry Potter and the Order of the Phoenix, Chapter 35 (Beyond the Veil)
  11. Harry Potter and the Deathly Hallows, Chapter 2 (In Memoriam)
  12. Dufftown, Scotland, United Kingdom Sunrise, Sunset, and Daylength
  13. Sunrise and sunset times in Dufftown, May 1995. timeanddate.com. Retrieved on 2022 April 22.
  14. Sunrise and sunset times in Dufftown, June 1995. timeanddate.com. Retrieved on 2022 May 5.
  15. Wikipedia:Venus
  16. Sky in Scotland
  17. Konstantin Bikos. Civil Twilight – Civil Dawn & Dusk. timeanddate.com. Retrieved on 2022 April 17.
  18. Konstantin Bikos. Astronomical Twilight – Astronomical Dawn & Dusk. timeanddate.com. Retrieved on 2022 April 17.
  19. Konstantin Bikos. Nautical Twilight – Nautical Dawn & Dusk. timeanddate.com. Retrieved on 2022 April 17.
  20. Sunrise and sunset times in Dufftown, June 1996. timeanddate.com. Retrieved on 2022 April 17.
  21. "Easter", The Calendar FAQ
  22. Quidditch Through the Ages, Chapter 7 (Quidditch Teams of Britain and Ireland)