This project creates a motion-based play system that allows pairs of people to create their own play. It is an investigation in scaffolding an emergent play creation process. In it, players are placed in a minimal environment, given control over a digital body that emits movement-generated effects, and play emerges based on how players choose to express these effects in paired play. This paper describes the research and development that drove the creation of the system’s underlying play model and architecture, as well as the results of user testing. A variety of research approaches were undertaken in the project, including readings, interviews, low/high-fidelity prototyping, system architectural design and coding. Relevant research was explored in the areas of play, open-ended play, emergent play, and digital performance. The core objectives of the research were to build the system and then validate its efficacy.