This paper describes the social actions called ‘affective actions’ that are implemented in the prototype multiplayer game world The Pataphysic Institute (PI). An aim of this paper is to demonstrate how a game mechanic can result in a certain set of dynamics or play patterns. Affective actions are but one feature of the many that make up the game world of PI. In this paper, the feature is used as a vertical slice into the game design. The aim is to, by using this slice, show the founding the principles of the game, the play tests that informed the design, as well as the play patterns that were observed as they emerged in a series of game mastered play–test sessions.