Mao is a
card game, the point of which is to
figure out the
rules.
Players give each other
penalty cards when someone breaks a
rule. The
winner of each
hand gets to add a new rule every time. This is mostly a game about
asserting your
superiority over those who don't know how to play, but it's really damn fun to watch your
friends go completely
postal when they end up with 11
cards in their hand by the end of the
game!
The only rule I can tell you is this one.
Watch for my upcoming node How to Play Mao, in which I will tell you how to play the game without telling you a single rule.