At the beginning of the evening you ask out loud. Who wants to play the bottle cap game. Chances are there will always be some willing people. Now you count how many people are playing. Then you subract one from that. And don't forget that number. Get everybody to simultaneously stick a bottle cap to their forehead. Object: Keep the cap on your forehead the longest. The first person to lose their cap has to drink as many people playing minus one drinks. And the next person has to drink 2 less and so on . Thus the winner does not have to drink at all.
Chris The Urinator