A stoner game. Played when a group of people pack one single bowl in a small pipe, and pass it around a circle. The person who cashes the bowl, inhaling the notoriously foul tasting "butt-hole hit" is then ridiculed and removed from the circle. A mix between duck-duck-goose, Russian-Roulette, and smoking. The game ends when the pipe is down to two people, at which point they pretty much win because they've smoked all the weed.
Dude, Nick always seems to win in Butthole-Roulette. He's such a chill bro!