CalvinBall is a game with only one rule, no rule can be used more than once. The game was originally created by Calvin in defiance of organised sport after he was ridiculed at school while playing baseball. All players must wear masks though as to why Calvin will only say “no one is allowed to question the masks”. The game uses various tools including flags, wickets and a ball (usually a soccer ball but any will do). Scoring appears to be completely random, with anything from ‘Q’ to ’12’ to ‘oogy’ to ‘boogy’ having been registered. The only person to have played the game apart from Calvin and Hobbes is Rosalyn who seemed to pick up the rules (or lack thereof) very quickly and win a game.