Pervasive games have some unique properties that make them difficult to teach and challenging to design. The best examples of pervasive games are all now unplayable, having been specifically situated in both space and time. Pervasive games can be big, comprised of large player communities and covering sizable geographies. They can take a long time to play, sometimes lasting weeks or months. This makes them cumbersome to iteratively playtest and inaccessible to most student game designers, who must rely upon written accounts and sparse documentation to imagine the game experience. In this paper we describe and reflect on the process of teaching pervasive game design through a playful in-class exercise that we deployed in the Spring of 2016.