Cruciatus Curse

"Voldemort raised his wand, and before Harry could do anything to defend himself, before he could even move, he had been hit again by the Cruciatus curse. The pain was so intense, so all-consuming, that he no longer knew where he was... white-hot knives were piercing every inch of his skin, his head was surely going to burst with pain; he was screaming more loudly than he'd ever screamed in his life-"

- Harry Potter as Lord Voldemort casts the Cruciatus on him.

The Cruciatus Curse (also known as the Torture Curse ) is one of the three Unforgivable Curses of the wizarding world. It is a curse of torture, inflicting excruciating pain on a victim. This makes it popular among the Death Eaters for use on both fellow wizards and Muggles. Considering the fact that this curse doesn't physically harm the victim, it is possible that it only stimulates pain receptors. When casting the curse one incants "Crucio." Whenever a person simply refers to using it, however, they instead say that they will "Cruciate" someone, or that they have "Cruciated" someone.

The two most well-known victims of this curse are the former Aurors Alice and Frank Longbottom, who were tortured into insanity with it by Death Eaters Bellatrix, Rodolphus, Rabastan Lestrange, and Barty Crouch Jr.

Harry Potter attempted to use this curse on both Bellatrix Lestrange and Severus Snape after people he cared about were killed. He later used this curse on Amycus Carrow, with a certain degree of success.

Performance
"You need to mean them, Potter! You need to really want to cause pain ... to enjoy it ... righteous anger won't hurt me for long ... I'll show you how it is done, shall I? I'll give you a lesson -"

- Bellatrix Lestrange to Harry Potter.

To successfully perform this curse, the wizard or witch must possess a deep desire to cause the victim pain. For example, despite being furious with Bellatrix Lestrange for her murder of his godfather in 1996, Harry Potter was only able to cause her a brief moment of pain with the Cruciatus Curse because he used it in "righteous anger," though he was still able to knock her off of her feet with it. He performed it more powerfully in 1998 on Amycus Carrow, who spat in Minerva McGonagall's face. Amycus was thrown into the air and knocked unconscious. This suggests that although Harry's curse was intense, he still lacked the fundamental sadism to inflict prolonged, excruciating pain with it. On the other hand, due to Bellatrix being a witch with great sadistic intents and no conscience, she was able to cast the curse with great potency, and seemingly had an affinity to it.

Effects
"At once, the spider's legs bent in upon its body; it rolled over and began to twitch horribly, rocking from side to side. No sound came from it, but Harry was sure that if it could have given voice, it would have been screaming. Moody did not remove his wand, and the spider started to shudder and jerk more violently..."

- Description of a spider under the Cruciatus Curse

The pain caused by the Cruciatus Curse is described as worse than "one thousand white-hot knives, boring into the skin." This pain can cause permanent mental injury, as in the case of the aforementioned Longbottoms, who spent the rest of their lives in St Mungo's Hospital for Magical Maladies and Injuries because of the trauma the curse caused. Presumably, such permanent effects occur if the victim is exposed to a particularly intense curse for a long period of time.

As Memory Charms can be broken through torture, the Cruciatus Curse is capable of such a feat, though it requires a certain level of exposure in time and intensity to break through it. Bertha Jorkins suffered such a trial, and the end results was that both her body and mind was damaged beyond repair.

If the curse hits an inanimate object, it may cause it to shatter instead.

Defence
Once cast, there is no spell that can defend against the Cruciatus Curse. However, there are still defensive options available against it. The spell can be dodged by hiding behind a solid object, and a particularly strong-willed wizard can merely resist the pain until the spell is lifted (though, as noted above, prolonged exposure can cause permanent mental damage). Another option is to interrupt the caster before they can finish speaking the incantation, as Severus Snape did to great effect against Harry Potter in 1997 by using Legilimency to anticipate the spells he would use.

Creation
The Cruciatus Curse was invented during the early Middle Ages, by dark witches or wizards. The curse was created for torture purposes, but has also been used effectively in duels. According to Barty Crouch Jr., the curse was once very popular.

Legal Status
The Cruciatus curse is one of the three Unforgivable Curses, which means it is illegal to perform on a fellow human being, unless one can prove they are under the effects of the Imperius Curse when performing it, as Viktor Krum did.

History of Use
"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 Cruciatus Curse was deemed by the Ministry to be dark magic, and, along with the Imperius and Killing curses, were declared "unforgivable" in 1717. The use of any of these three curses on a fellow human being would result in a life sentence in Azkaban (unless there was sufficient evidence that the caster did so under the influence of the Imperius Curse or for other defensible reasons)

During the First Wizarding War, when Barty Crouch Sr. was in charge of the Department of Magical Law Enforcement, he fought violence with violence, and legalised 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.

Shortly after Voldemort's defeat, four Death Eaters — three Lestranges Bellatrix, Rodolphus and Rabastan, along with Barty Crouch Jr. — captured the Auror Frank Longbottom and his wife Alice and tortured the two with the Cruciatus Curse for information for Voldemort's whereabouts. This usage of the curse caused the couple to become insane, and was considered to be the most atrocious and infamous act within history.

Despite the repeal of the curse's legal usage, 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. However, since the use of the curse was illegal only on a fellow human being, the demonstration of the curses on the spider may have been within legal boundaries. Dolores Umbridge, in a last-ditch efforts to draw information from Harry Potter, almost used the curse on the boy, under the presumptions of that as long as the Minister is not notified, and that he would understand even if he did due to what they would deem as circumstantial reasons. About a year later, Draco Malfoy, in a fit of rage and recklessness, attempted it on an eavesdropping Harry.

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: students were required to practice the Cruciatus Curse on other students who earned detention, and the Carrow siblings used it to punish students as they see fit. Harry Potter managed to successfully use it on Amycus Carrow without legal consequences as well as a result of this legalisation. After Voldemort's death and the revolutionising of the Ministry under new Minister for Magic Kingsley Shacklebolt, the three curses were once again forbidden.

Harry Potter had a vision of Lord Voldemort ordering Draco Malfoy to use the curse on Thorfinn Rowle after he and Antonin Dolohov failed to capture Harry at Tottenham Court Road. Although he saw nothing of Dolohov's punishment, Narcissa Malfoy later mentioned "what he did to Rowle and Dolohov" when she was afraid to contact Voldemort.

Possible uses

 * As Harry Potter chases Severus Snape away from Hogwarts at the end of the Battle of the Astronomy Tower, he is hit from behind by a curse cast by one of the Carrow siblings. Although we never hear the incantation, he falls to the ground, screaming, and momentarily loses track of what's going on. This description, coupled with the fact that the Carrows had been trying to curse him all the way down from the Astronomy Tower, makes it likely that he was hit by the Cruciatus Curse.
 * Since Luna was held prisoner at Malfoy Manor for months, it is likely she was also tortured with it.
 * After Harry, Ron, Hermione, and the other prisoners escaped from Malfoy Manor, Harry had a vision of Voldemort punishing the Malfoys, but whether he used the Cruciatus Curse was not mentioned.

Etymology
Crucio means 'I torture'. Cruciatus takes its name from the Latin word for "pain" or "torture," the root of which can be seen in other words such as "excruciating" and "crucifixion."

Behind the scenes

 * When Harry Potter attempts to cast this spell on Bellatrix Lestrange, a ball of red light is fired from the tip of his wand, most likely because his spell was cast with "righteous anger". not outright sadism. The spell still had enough force to knock Lestrange off her feet.
 * In the video game adaption of Harry Potter and the Goblet of Fire the curse  is used by Death Eaters in the beginning and it looks like a jet of green light that is capable of making explosions or knocking down trees. It's not entirely known whether this was the Cruciatus Curse or the Killing Curse.
 * In the console version of Harry Potter and the Order of the Phoenix the cutscene where Umbridge is taken into the Forbidden Forest she uses the Curse instead of Incarcerous and it looks like a flash of green light that strikes the centaur, however in the scene where Harry chases Bellatrix through the Ministry he casts it and it looks like Expelliarmus which was a yellowish-white in color and it blasted her off her feet.
 * Severus Snape once asserted Harry Potter had neither the nerves nor the skill to perform Unforgivable Curses. However, less than a year later, Harry succeeded in cursing Amycus Carrow. - This move was met with criticism by some fans, who felt that Harry had sunk to the same level as his enemies in using it in such a manner. J.K. Rowling countered such criticism by asserting that "Harry is not, and never has been, a saint", and that he has flaws of character like everybody else.
 * In the film adaption of Harry Potter and the Goblet of Fire instead of using three spiders Barty Crouch Jr. uses one special kind of spider, an Amblypygi.
 * In the original script of the film adaptation of Harry Potter and the Half-Blood Prince, Harry Potter said "Cruciatus" while battling Severus Snape in Hogwarts grounds instead of using the real incantation which is "Crucio".
 * In LEGO Harry Potter: Years 1-4, only Dark Wizards, including Peter Pettigrew, Lord Voldemort, and Barty Crouch Jr. can use Dark Magic, which consists of the Killing Curse (Peter Pettigrew is the only LEGO Dark Wizard who can't use Avada Kedavra) and the Cruciatus Curse. Whenever a Dark Wizard uses the Levitation Charm on a person, it instead changes to the Cruciatus Curse. When this is used, the pink light of the Levitation Charm is missing when targeting a person, but replaced by a blood red. the victim hovers several feet off the ground, and purple lights emits from their joints. After a few seconds, they die.
 * In Harry Potter for Kinect Voldemort can use this spell against Harry in the final battle during Voldemort's Last Stand as they engage in a normal duel.

Appearances

 * 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 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 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
 * Harry Potter and the Deathly Hallows: Part 2 (video game)
 * The Tales of Beedle the Bard
 * LEGO Harry Potter: Years 1-4
 * LEGO Harry Potter: Years 5-7
 * Harry Potter: Spells
 * Harry Potter for Kinect

Notes and references
Cruciatus-Fluch Maldición Cruciatus Sortilège Doloris