For questions about the Unforgivable Curses (Crucio, Imperio, and Avada Kedavra) in the universe of Harry Potter. Always use together with the [harry-potter] tag.
The Unforgivable Curses are the three most 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, which kills instantaneously and leaves no visible signs of death;
- the Cruciatus Curse Crucio, which causes intense pain;
- the Imperius Curse, Imperio, which binds another person or creature to the spell-caster's will.
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Wizarding War, while under Lord Voldemort's regime in 1997-1998, the curses were made legal, though this was presumably repealed following Voldemort's demise.