It's pretty fun. You sit in a circle with other people, and then someone starts off by whispering a message to the person on their left. Then that person whispers what they heard to the next person. And so on and so on, until you go around the circle. Since you're whispering so quietly that nobody else hears, you'll often mishear things. And the game is finding out how much the message changes by the time it gets back to the original person.