The Imperius curse is one of Unforgivable Curses which can put a victim completely under the caster's control.
How long does its effect last?
Can it be used to make a person a slave for a lifetime?
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Sign up to join this communityThe Imperius curse is one of Unforgivable Curses which can put a victim completely under the caster's control.
How long does its effect last?
Can it be used to make a person a slave for a lifetime?
It seems to depend on the ability of the caster as well as susceptibility of the victim, rather than a spell having any particular duration of effect
Example:
(Fake) Moody's curse on Harry seems to last only for a few minutes because Harry is constantly fighting back (however, he might even have purposefully put a weaker curse on Harry so that he would be able to fight it off)
Barty Crouch Sr.'s curse on Barty Crouch Jr. seems to last for months until Jr. eventually begins to be able to fight it off, and in this case it is a powerful wizard casting the curse on a relatively powerful victim
Voldemort's curse on Barty Crouch Sr. also seems to last for months until he begins fighting it off, but by this time he seems to have gone almost mad due to it's effects
Harry's curse on the Goblin and a Death Eater in the final book seems to last for quite a while, but it is also implied that he is continuously casting the curse on them, so needs to be in front of them to keep renewing it's effect
It has also been explained that after the fall of Voldemort in the First Wizarding War the imperioused all over the country started coming out of the curse, which means Voldemort wasn't always with them to continuously renew the strength of the curse, but rather cast it on them once and then left them to go about their work. This also seems to imply that the effect of the spell probably lasted for a fair amount of time
So it's probably not possible to say how long the curse applied on a victim will be in effect (like a drug), but rather depends on the strength of the caster, victim, as well as the strength of the curse itself