Twilight has grown tired of pinkie's childish board-games, and strategic games like chess and battle-cloud are getting old fast, what with half her opponents cheating or generally lacking interest in a proper game.
Purple Smart was faced with an incredible lack of mentally challenging things to do with another pony, so she takes matters into her own hooves.

Using all of the resources (mostly books) available to her, Twilight has created the ultimate game that has a perfect mix of brains and Fun Physical Activity to be a hit with everypony.

Spike doesn't like it.