Boom! All you need is a bunch of people, small glass and a bottle of anything alcoholic. It is about numbers. You can play this game on any prime number. For example, on 7. The one who starts says 1, the person beside him says 2, and so onin a circular way. When someone has to say number 7, or a number that is divisible by 7 or contains digit 7, he have to say Boom! and the circle turns. Who mistakes, drinks, and starts a new round. It gets really interesting after 5 or 6 rounds.