There's nothing quite as hilarious as playing an epic prank on one of your friends. Sure, you love 'em, but it's fun to watch them squirm a little. So when is the best time to play a prank on a friend? When they're drunk, of course!
If you have a wasted friend that doesn't know up from down, it's time to take advantage of their temporary stupidity. Obviously if they are beyond wasted, maybe take them to the hospital and make sure they're alright. But, if your friend is just drunk and out of harms way, it's time to mess with them.
But some people take pranking a little too far. If you put your drunk friend in danger by locking them out in the snow or burying them in sand before high tide, then you are pure evil.
So please, prank wisely. You don't want someones hospitalization on your conscience.