Not me but my husband's friend, not even a dare: a prank. Friend x had passed out drunk on the couch. Friend y came up with a stupid idea to put a drop of (I can't remember what liquor, let's say...) vodka on friends x's jeans and then light it on fire for a second before blowing it out. They did so and everyone drunk laughed. So he did it again. Everyone laughed again and I think at this point they wondered how long they could keep doing it before friend y would wake up.

You guessed it. Friend y put another drop of vodka on friend X's jeans and as he was lighting it on fire, knocked the remainder of the bottle on him. He lit up on fire, woke immediately and freaked out, started running around screaming. Everyone else drunk had no idea what to do but was apparently running back and forth from the kitchen back to him with saucepans full of water that were mostly ending up on the floor because friend x was running around in agony and a hard target for said water. Apparently bits of flesh were melting off.

Eventually they got him into a cold bath, waited for ambulance to come. Apparently still melting flesh. Poor fucking guy. They were all so dumbfounded and freaked out when he left in the ambulance that they decided that they may as well clean up all the mess.

Police came later, reallllly pissed that they'd cleaned, as it was a crime scene. The guy lived, but woth lasting damage obviously, and they were all let go but for ages the cops would give them shit when they saw them, they basically believed that they all had tried to kill him and covered the evidence so there was no proof.

My husband ran into him a while later and asked how he was going, he basically said he knew it was an accident but couldn't be friends with any of them.

I don't blame him. Accident or not, it was a stupid prank with permanent damage to the poor guy.