Killing Curse

"Avada Kedavra's a curse that needs a powerful bit of magic behind it - you could all get your wands out and point them at me and say the words, and I doubt I'd get so much as a nosebleed."

- Barty Crouch, Jr. as Alastor Moody

The Avada Kedavra Curse (also known as the Killing Curse ) is a spell that causes instantaneous death and is one of the three Unforgivable Curses.

The only known counter-spell is Sacrificial protection. However, one may dodge the green bolt or block it with a physical barrier. The Killing Curse, as an "unblockable" Curse, cannot be intercepted by another spell, except in circumstances of Priori Incantatem, where the caster and his opponent's wands and spells are locked together. An explosion or green fire may result if the spell hits something other than a living target.

Only two wizards are known to have survived blows from this deadly curse: Harry Potter and Lord Voldemort. Harry survived two direct attacks: once in 1981 after his mother's self-sacrificing love protected him from Lord Voldemort, and once in 1998 after the curse, cast again by Voldemort, served only to destroy the fragment of the dark wizard's soul that lived in Harry. Lord Voldemort remained alive after the aforementioned curse from 1981 rebounded and struck him because of his Horcruxes. Voldemort was notorious for using this curse regularly and indiscriminately. Its incantation is Avada Kedavra.

Creation
The Killing Curse was invented during the early middle ages, by dark witches or wizards. The curse was created primarily as a means of quickly and efficiently slaying one's opponent in a duel.

Legal status
"The Cruciatus, Imperius and Avada Kedavra Curses were not made "unforgivable" until 1717."

- Albus Dumbledore

After the Wizards' Council was reformed into the Ministry of Magic tighter restrictions were placed on the use of certain kinds of magic. The Killing Curse was deemed by the Ministry to be dark magic, and, along with the Cruciatus and Imperius curses, were declared "unforgivable" in 1717. Cursing another human with the Killing Curse would carry the punishment of a life sentence in Azkaban.

However, the First Wizarding War, when Barty Crouch Sr. was in charge of the Department of Magical Law Enforcement, he fought violence with violence, legalising the three Unforgivable Curses for Aurors against the Death Eaters in order to win the war. This was repealed once the war was over as it was no longer necessary, though, in the 1994–1995 school year, Barty Crouch Jr. (under the disguise of Alastor Moody) showed these three curses to his fourth year classes on spiders despite the Ministry's disapproval.

When Lord Voldemort took over the Ministry, the three curses were once again legalised: this time every wizard and witch had the right to use them as they please. In fact, they were practiced in Hogwarts as part of the curriculum of Dark Arts class under the tutelage of Professor Amycus Carrow. After Voldemort's death and the revolutionising of the Ministry under Minister Kingsley Shacklebolt, the three curses were once again forbidden.

It should be noted that despite the curse being illegal, references have been made to Aurors using deadly force against opponents, though whether this means they were authorized to use the killing curse specifically is unclear. Despite the circumstances, it is unknown whether the Killing Curse was used by anyone but Voldemort and his Death Eaters during the Battle of Hogwarts. It is also known that use of this curse may go unpunished if there is sufficient evidence that the caster did so under the influence of the Imperius Curse.

Nature
Obviously, when the curse hits a living, organic target it invariably kills them. However, when this curse hits an inanimate target the effect varies: it can produce small fires, small greenish explosions, or explosions of such intensity that can blow up an entire story of a cottage. However, certain objects, such as the centaur statue of the Fountain of Magical Brethren, managed to block the curse without any visible damage to itself.

It should be noted that curse did not terminate the animation of (i.e. "kill") the statue, however, the statue was only animated by magic and so presumably had no real life in him for the curse to take away.

Performance
The curse requires a great deal of magical talent to perform correctly. In 1994, Barty Crouch, Jr., disguised as Alastor Moody, claimed that, if all of the students before him were to get out their wands and perform it on him at one time, he would probably get nothing more than a nosebleed. However, as his loyalties were with Lord Voldemort, it is unknown to what extent his words were accurate. It is possible to cast the curse nonverbally, as Bellatrix Lestrange released a green light to kill a fox without incantation. Large amounts of concentration is likely required to cast the Killing Curse, which is probably why Death Eaters don't use it as their primary offensive spell.

Signs


The Killing Curse is described as a jet of blinding green light followed by a rushing sound, which causes the victim instant death. Victims of the Killing Curse are identified by the fact that they simply appear to have dropped dead for no biological reason. Indeed, victims seem "perfectly healthy" apart from the fact that they are dead

Sensation
Presumably, the Killing Curse does not inflict any pain on its target, since it causes instantaneous death. However, Harry Potter, awaking after a Killing Curse cast by Lord Voldemort hit him, describes the sensation as an "iron-clad punch."

Survivability
The Killing Curse can be dodged or physically blocked by an object, such as the statues Dumbledore animated to protect Harry Potter during his duel with Voldemort after the Battle of the Department of Mysteries.

The Killing Curse is known to be unblockable, as once it strikes the living victim, it almost always results in immediate death. There is "no counter-curse" since it is not possible to revive the dead. However there are some exceptions.

Sacrificial Protection
The most effective method of surviving the Killing Curse is through Sacrificial Protection. The sacrifice of one's life for another, a manifestation of love, is the most potent defense against the "unblockable" Killing Curse. Harry Potter, was saved by his mother, Lily Evans, lovingly sacrificed herself when she shielded her son with her body, making him the first known survivor of this Curse. Harry Potter was the only person known to have survived Avada Kedavra with no ill effects

Horcruxes
Another defense employed against the Killing Curse is the creation of Horcruxes. The creation of Horcruxes is a preventive measure, created by a wizard long before he faces an actual Killing Curse attack. However, this is less effective than Sacrificial Protection, since it only allows a little more than the soul of the target to live, while the target's body still dies.

When the Killing Curse of Lord Voldemort backfired with his attempt to kill Harry in 1981, his Horcruxes tethered his soul to life. The Curse drove his mangled soul from his body and split his unstable soul, leaving him to roam only as a shadowy spirit.

Priori Incantatem
The Priori Incantatem effect allows a wizard to "intercept" the "unblockable" Killing Curse. However, since wands with twin cores are extremely rare, this method cannot be employed "at will".

Priori Incantatem occurred in the duel between Harry Potter and Lord Voldemort in the graveyard during Harry's fourth year.

Phoenixes
Phoenixes are semi-protected from the Killing Curse, due to them being immortal. In 1996, Fawkes swallowed one intended for Albus Dumbledore, causing him to burst into flame and die instantly. However, he then was reborn from his ashes.

Other
The following are speculations on why only the Horcrux inside Harry Potter, and not Harry himself, had been killed by the Killing Curse in the Forbidden Forest.

Blood within Lord Voldemort
During his resurrection, Lord Voldemort used Harry's blood in reconstructing his body. According to Albus Dumbledore, since Harry's blood contained Lily's protection, and Voldemort took this blood for himself, Voldemort had unknowingly protected Harry from death, as long as he himself lives.

As such, the Sacrificial Protection lingering in Harry's blood, which Voldemort took, is similar to but superior to that of a Horcrux's. While a Horcrux requires the preservation of a piece of the soul within an object, blood with Sacrificial Protection required the preservation of the blood within another living entity. While a Horcrux protects the soul from death, blood with Sacrificial Protection is almost as good as Sacrificial Protection; it had the little side effect of Harry feeling an "iron-clad punch" after awakening.

During a discussion with Severus Snape, Dumbledore had specified that it is essential to the plan that Voldemort himself must [kill Harry]. Whether this is because only Voldemort can kill his own Horcrux within Harry, or whether the blood protection would only work specifically with Voldemort (Voldemort being the one from whom Lily had been protecting Harry) is unknown.

Mastery of the Elder Wand
Since the Elder Wand "does not harm its true Master", it is possible that the Killing Curse casted by Lord Voldemort, using the Elder Wand, of which Harry is the Master, had no effect on Harry at all. This may explain why Harry lived, while the Horcrux inside him was destroyed, instead of killing both of Harry and the Horcrux.

Mastery of the Deathly Hallows
When the Killing Curse hit Harry Potter for the last time, Harry had in his physical possession two of the three Hallows - the Resurrection Stone and the Cloak of Invisibility. In addition, he was recognized by the Elder Wand as its "true Master". It is possible that Harry had essentially become the Master of Death at that point. However, it is still uncertain what being the Master of Death truly means, especially whether it really protects the Master from Death.

However, it remains a possibility, since neither Sacrificial Protection nor simple Mastery of the Elder Wand would have explained the curious limbo effect wherein Harry was able to speak to the spirit of Dumbledore. Also, the option of whether to return or to go "On" could only be satisfactorily explained in the perspective that Harry had been Master of Death. In the first two theories, Harry had no option to go "On". Sacrificial protection would protect him without giving him the option whether to die or to continue living, while as Master of the Elder Wand, the spell would not have harmed him at all. The option of whether to return or to go "On" is consistent with the concept of the Master of Death - a Master of Death accepts death as inevitable (hence, the choice to go "On"), as well as making him the "Conqueror" of Death (hence, the choice to return).

Known practitioners

 * Bartemius Crouch Jr.
 * Bellatrix Lestrange
 * Lord Voldemort
 * Peter Pettigrew
 * Severus Snape (On Albus Dumbledore's Orders)
 * Thorfinn Rowle
 * Vincent Crabbe
 * Other Death Eaters and Dark Wizards

Etymology
Avada Kedavra is based on the Aramaic עַבְדָא כְּדַברָא, avda kedavra, meaning "what was said has been done." This phrase is also the origin of abracadabra, which, like hocus pocus, is used by magicians as a magic word when they perform tricks.

During an audience interview at the Edinburgh Book Festival on 15 April, 2004, J. K. Rowling had this to say about the spell's etymology: "Does anyone know where avada kedavra came from? It is an ancient spell in Aramaic, and it is the original of abracadabra, which means 'let the thing be destroyed.' Originally, it was used to cure illness and the 'thing' was the illness, but I decided to make it the 'thing' as in the person standing in front of me. I take a lot of liberties with things like that. I twist them round and make them mine."

"Kedavra" also sounds very similar to the English word cadaver, which means "corpse," and derives from the Latin cadere, "to fall."

Behind the scenes

 * The biological reasons for the victim's death have never been fully explained. It is possible that the victim's internal organs cease function, or that once the spell hits a person's body, it simply kills every living cell in the victim's body. It could also cause sudden brain death, simply stopping the progress of every electrical synapse in the brain simultaneously by draining all potential energy there. In addition to this, it is possible that it causes a person's soul to "pass on", and leave the body, similar to when the body dies naturally, and the soul passes on into whatever afterlife there may be.
 * In the film adaptation of Harry Potter and the Chamber of Secrets, Lucius Malfoy says "Avada" at Harry Potter after he unwittingly frees Dobby. Dobby knocks Lucius backwards with magic to protect Harry, and he does not finish the incantation. The part of the incantation shown, for plot reasons, was not represented in the subtitles. However, on the DVD if the audio is set to Spanish, Lucius says what it sounds like "Arara" in a more of a shouting way than hissing. It should be noted that Lucius Malfoy saying "Avada" was an ad-lib by his actor Jason Isaacs, as the script did not specify which curse he was supposed to use in the scene, so he used the first curse that came to his mind.
 * In the film adaptation of Harry Potter and the Order of the Phoenix, Bellatrix Lestrange is shown using the Killing Curse to murder Sirius Black in a scene fundamentally different from that of the novel, in which Sirius was pushed through the Veil by an unidentified red-coloured curse cast by Bellatrix. The effect of the curse is also not shown to be instantaneous in the film.
 * In Harry Potter and the Prisoner of Azkaban, Sirius Black and Remus Lupin intended to kill Peter Pettigrew for his betrayal of James and Lily Potter. It is unknown how they wanted to do it, possibly by the use of this curse. If it would have been used, Peter would have died the same way as his former friends.
 * Out of the three, the Killing Curse is the only Unforgivable Curse that Harry did not use.
 * After Harry Potter survived a second killing curse, he described it as having left a bruise that felt like an "iron-clad punch."
 * In the Harry Potter Lego game, Frank Bryce is replaced by a milkman. However, his death by this curse cannot be considered canon as no echo of him appeared during the Duel in Little Hangleton.
 * In the film version of Harry Potter and the Half-Blood Prince, when Snape kills Dumbledore, the curse appears to be blue rather than the usually green colour.
 * In Harry Potter and the Deathly Hallows: Part 2, Voldemort kills Pius Thicknesse with the Killing Curse after the latter interrupts the former's thoughts. It is unknown if Pius survived the Battle of Hogwarts in the book, but it is certain that Voldemort did not kill him.
 * While the curse is noted to be unblockable, in Part 2 of the final film Harry is seen blocking it many times from Voldemort, Ginny blocking it from Bellatrix, and Bellatrix blocking it from Molly Weasley twice despite it being unblockable with a Shield Charm.
 * The Killing Curse is not the only spell that can cause death to a living creature. Other spells may cause grievous injury, such as Fiendfyre, Sectumsempra, Antonin Dolohov's curse, the Blasting Curse, or an overuse of the Stunning Spell. Furthermore, it's likely that many spells can potentially cause death under certain circumstances, such as Impedimenta off a cliff, Diffindo across the throat, etc. However, this is the only spell whose sole and primary application is to cause death.

Appearances

 * Harry Potter and the Philosopher's Stone
 * Harry Potter and the Philosopher's Stone (film)
 * Harry Potter and the Philosopher's Stone (video game)
 * Harry Potter and the Chamber of Secrets (film)
 * Harry Potter and the Goblet of Fire
 * Harry Potter and the Goblet of Fire (film)
 * Harry Potter and the Goblet of Fire (video game)
 * Harry Potter and the Order of the Phoenix
 * Harry Potter and the Order of the Phoenix (film)
 * 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
 * Harry Potter and the Deathly Hallows: Part 1 (video game)
 * Harry Potter and the Deathly Hallows: Part 2
 * The Tales of Beedle the Bard (real)
 * Lego Harry Potter: Years 1-4
 * Harry Potter: Spells

Notes and references
Avada Kedavra Avada Kedavra Sortilège de la Mort Авада Кедавра