Last month, Tom Armitage wrote an excellent post about consensual play. The term denotes a subset of emergent gameplay1 which relies on both players agreeing to rules of conduct that are not enforced by the game itself.
Tom’s post was also my first exposure to Grifball, a sport-like player-created game mode in Halo 3. Robust mapmaking tools and heavy official support now make it a poor fit for the consensual model2, but Grifball remains interesting both as a case study for emergent gameplay and as a unique well-balanced game mode.













