The current passion at our home is chess. We've all been playing lots and often have a game going in the background even when we're off doing something else, which we'll pick up, play a few moves, then leave it for a while again. The kids have been learning to play off and on for a while now, and Sam has recently decided to start playing seriously by the rules. As the kids have learned to play, they've alternately played with rules and just played imaginatively, either making up their own rules or playing with the pieces in altogether different ways. We've just always followed their lead. Sam's favorite way to play for a while was with me using the rules of the game and talking out how the different pieces moved while he moved his pieces in any direction, any number of spaces to take my pieces one after the other. He just recently decided that really wasn't a fun way to play anymore once he'd grasped the rules and really wanted to play for real.
Emily got interested in chess a couple years ago, so we got her a computer program called Learn to Play Chess with Fritz and Chesster. She played with it off and on, but recently the kids have rediscovered it, and Julia's been playing with it non-stop, valiantly battling King Black. It's cool to watch their critical thinking and problem solving evolve. I've been playing with them either fully or with a handicap if they choose, and they're really getting quite good. It won't be long before they'll be able to beat me pretty consistently, I'm guessing. Even Sam, at age 5, has a really good grasp of the board and can anticipate different attacks and think non-linearly with his knights.