Unforgivable Curses
Unforgivable Curses are the three most powerful and sinister spells known to the wizarding world, and are tools of the Dark Arts. They were first classified as "Unforgivable" in 1717. They are the Killing Curse, Avada Kedavra, the Cruciatus Curse, Crucio, and the Imperius Curse, Imperio.
Using any of these three curses on another human being, muggle or wizard, will result in a life sentence to Azkaban, unless there is sufficient evidence that the caster did so under the influence of the Imperius Curse. Aurors were permitted to use them during the First Wizarding War, while under Lord Voldemort's regime in 1997-1998, the curses were made legal,[citation needed] though this was presumably repealed following Voldemort's demise.
Using any of these three curses on another human being, muggle or wizard, will result in a life sentence to Azkaban, unless there is sufficient evidence that the caster did so under the influence of the Imperius Curse. Aurors were permitted to use them during the First Wizarding War, while under Lord Voldemort's regime in 1997-1998, the curses were made legal,[citation needed] though this was presumably repealed following Voldemort's demise.