Marauder's Map

"Messrs. Moony, Wormtail, Padfoot, and Prongs Purveyors of Aids to Magical Mischief-Makers are proud to present THE MARAUDER'S MAP"

- The Marauder's Map

The Marauder's Map is a magical document that reveals all of Hogwarts School of Witchcraft and Wizardry. Not only does it show every classroom, every hallway, and every corner of the castle, but it also shows every inch of the grounds, as well as all the secret passages that are hidden within its walls and the location of every person in the grounds, portrayed by a dot. It is also capable of accurately identifying each person, and is not fooled by animagi, polyjuice potions, or invisibility cloaks. It can also reveal secret passages the Marauders found, though it only did this on one known occasion (in his third year, Harry Potter was shown how to use the statue of the humpbacked witch to enter Hogsmeade Village).

Creation
The Marauder's Map was created by Remus Lupin (Moony), Peter Pettigrew (Wormtail), Sirius Black (Padfoot), and James Potter (Prongs) while they were attending Hogwarts. The map was created between 1975 and 1978, because the titles on the map refer to these four men in their Animagus forms, and as for Remus Lupin in werewolf form, respectively. This artifact proved quite useful to the foursome (commonly termed "the Marauders") through the years, though at some point Argus Filch confiscated it.

Fred and George Weasley
"This little beauty's taught us more than all the teachers in this school."

- Fred Weasley on the Marauder's Map

Fred and George Weasley "nicked" the map from Filch's office in their first year at Hogwarts. They had to experiment with it in order to learn how to get it to work, but it gave them clues, "flickering into life here and there" when they came close to the activating phrase, until finally they got it exactly. Because of this map, the twins memorized the secret passageways of Hogwarts which they used for quite a few of their many pranks. In 1993, they gave the map to Harry Potter, so that he could go to Hogsmeade on the weekends, although he had not obtained a permission slip to do so from his guardians.

1993-1995
"Mr. Moony presents his compliments to Professor Snape and begs him to keep his abnormally large nose out of other people's business. Mr. Prongs agrees with Mr. Moony and would like to add that Professor Snape is an ugly git. Mr. Padfoot would like to register his astonishment that an idiot like that ever became a Professor. Mr. Wormtail bids Professor Snape good day, and advises him to wash his hair, the slimeball."

- The Map's response to Severus Snape's attempt to reveal the Map's secrets

Harry used the Map throughout his time as a student at Hogwarts, especially during his third year, when he tried to find his way into Hogsmeade. Then, he used the One-Eyed Witch Passage which led into Honeydukes cellar. The map however will insult anyone who doesn't know how to activate it.

During his fourth year, Harry used the map to help him as he sneaked into the prefects' bathroom to work on his clue for the Second Task of the Triwizard Tournament. On his way back, he dropped the map, and it was almost taken by Severus Snape. Harry was saved by Barty Crouch Jr., disguised as Professor Alastor "Mad-Eye" Moody who pretended it was his. Crouch later asked to borrow the map from Harry, but after Crouch was unmasked, he reclaimed it.

1996-1998
During Harry's sixth year, when he spent a great deal of time obsessing over Draco Malfoy's daily activities, he used the map often.

When monitoring Draco Malfoy, Harry found he often disappeared off the map. The cause of this was not revealed until after he asked Dobby to trail Draco to find out what he was doing when he disappeared off the map. Dobby discovered that Draco was disappearing into the Room of Requirement, which was not on the Marauder's Map. Whether because it was Unplottable or the Marauders never found the room is unspecified.

While on the run in Deathly Hallows Harry would often look at the map to see what Ginny Weasley, his ex-girlfriend, was doing.

Harry Potter's legacy
After Harry Potter's defeat of Lord Voldemort during the Battle of Hogwarts, the map would not have been used for many years. Eventually, James Sirius Potter would steal the map from his father's desk.

Use
The map is normally disguised as a blank piece of parchment. To view the map, one must tap it with one's wand and recite, "I solemnly swear that I am up to no good." The content of the map will reveal itself.

To hide the contents of the map so the parchment appears blank again, one must again tap it and recite, "Mischief managed."

If someone tries to view the map without reciting the proper incantation, the map merely insults them and tells them to mind their own business. Severus Snape experienced this phenomenon when he tried to view the map by force.

An added bonus is that if the bearer of the map approaches the entrance to a secret passage protected by a password, the password will appear on the map.

Exceptions to use
"I solemnly swear that I am up to no good."

- Words to reveal the map.

In some rare cases, the map may not be used to the best of its ability. Heading out through the secret passage from the Whomping Willow to the Shrieking Shack will make the person disappear, as Snape mentions in the spring of 1994, so the Shrieking Shack is not included on the map because it goes off the edge of the map. It also does not show any person that may be inside the Room of Requirement, as the Room of Requirement is unplottable and it itself does not show up on the map, or the Chamber of Secrets, as it is very unlikely that any of the creators of the map knew of its existance at the time that the map was made.

Special abilities of the map
More importantly, the Map shows the name and location of every person within the Hogwarts grounds, even if they are wearing an Invisibility cloak (as demonstrated when Remus Lupin saw Harry Potter, Ron Weasley, and Hermione Granger sneaking to Rubeus Hagrid's hut under an Invisibility cloak), transformed animagi (evidenced by Lupin seeing Peter Pettigrew return to the school grounds from Hagrid's, despite being disguised as the rat Scabbers at the time), or under the influence of the Polyjuice Potion (as demonstrated when Harry saw Barty Crouch Jr., at the time disguised as Alastor Moody, ransacking Snape's office for more Polyjuice ingredients).

Behind the scenes

 * The Marauder's Map, along with Harry's wand and the Cloak of Invisibility are Harry's only remaining treasures from his time at Hogwarts.
 * According to J. K. Rowling, Harry never gave the map to Teddy Lupin or any of his children, but his son James probably stole it out of Harry's desk.
 * The magical defences on Hogwarts have been mentioned several times, including Hogwarts being unplottable. That implies that mapping Hogwarts is impossible, which is exactly what the Marauder's Map does. There are some possible loop holes for this: for example, making a place unplottable might simply make it impossible for it to be mapped with reference to somewhere else. As the Marauder's Map only covers Hogwarts, not of its position relative to (for example) London, it would circumvent the theoretical unplottable charm.
 * The claim that the map shows "every" corner of Hogwarts is likely an exaggeration, as there is no indication that it shows the Chamber of Secrets or the Room of Requirement. However, the map was created based on the Marauders' knowledge of Hogwarts and as none of them were Parselmouths, they would not have been able to access the Chamber of Secrets. Considering that Fred and George had it during the opening of the Chamber of Secrets, and the disappearance of their sister into it, it seems very unlikely it showed the Chamber or they would have mentioned it. Also, it is possible that they did manage to find the Room of Requirement, but that the room itself is unplottable as need be . However, it is not very likely the Marauders did discover the Room of Requirement as Sirius never suggested the Room to Harry as a possible location for the meetings of Dumbledore's Army in Order of the Phoenix. It is also possible that Sirius didn't think about the Room of Requirement at the time.
 * In the book, the map is described as a single piece of parchment that could be laid on a desk in a classroom. In the movie, the map is shown as a rather large, much-folded paper with several unfolding flaps within it. This is actually more practical, as it is unlikely that all of Hogwarts—having many floors and towers—could be drawn on a single piece of paper.
 * In the film adaptation of Harry Potter and the Half-Blood Prince, one page is added to the Map, featuring the seventh-floor corridor.
 * There is a toy version of the Map in every copy of the video game version of Harry Potter and the Order of the Phoenix, which is an exact replica of the in-game Map.
 * A real-size replica of the Marauder's Map prop can be bought at Noble Collection.
 * In the film adaptation of Harry Potter and the Prisoner of Azkaban, Moony is misspelled "Mooney" as an inside joke to the film's visual effects supervisor, Karl Mooney.
 * Harry retrieved the Marauders Map when Barty Crouch Jr. took it, by simply taking it from the fake Moody's office at the end of the school year.
 * Fred Weasley told Harry that the marauders map had taught them more than all the proffesors in the school, which is ironic, considering that one of the creators of the map (Moony) was currently a proffesor, at that point.

Appearances

 * Harry Potter and the Prisoner of Azkaban
 * Harry Potter and the Prisoner of Azkaban (film)
 * Harry Potter and the Prisoner of Azkaban (video game)
 * Harry Potter and the Goblet of Fire
 * Harry Potter and the Order of the Phoenix
 * Harry Potter and the Order of the Phoenix (film)
 * Harry Potter and the Order of the Phoenix (video game)
 * Harry Potter and the Half-Blood Prince
 * Harry Potter and the Half-Blood Prince (film)
 * Harry Potter and the Half-Blood Prince (video game)
 * Harry Potter and the Deathly Hallows
 * Harry Potter and the Deathly Hallows: Part 1
 * The Wizarding World of Harry Potter
 * Lego Harry Potter: Years 1-4

Notes and references
Carte du Maraudeur Карта мародёров מפת הקונדסאים