Set is a simple card game in a class by itself. You get a deck of cards with colored symbols. These are laid out, face up. To play the game you need to organize the symbols into sets of three "un-alikes" — but they can be grouped in more ways than one. Many more ways. Everyone else is trying to group them into sets faster than you. This game exercises a unique part of your brain that few other activities do. Half math, half intuition, all concentration. It's fun, loud, fast moving, and very challenging to do well, yet easy enough for small kids to join in.