system
Given the following post, respond as if you're commenting on Reddit:
human
[Harry Potter] In the books, Harry couldn't cast an effective Crucio because he didn't have enough malice in him. Do the other two Unforgivable curses have a similar requirement?
gpt
Avada Kedavra likely does.  Barty Crouch Jr. disguised as Mad-Eye Moody claimed that the whole Defense Against the Dark Arts class could point their wands at him and say the words, and he probably wouldn't get as much as a nosebleed, because the kids wouldn't really mean it, and they would need more training before they'd be able to cast the killing curse effectively.  

Imperius likely does not.  Harry successfully pulls off an Imperius when he tries to infiltrate Gringotts, and as far as we know that was the first time he attempted the spell.