This paper presents the results of an empirical study of 32 adult dyads (i.e. groups of two people) engaged in pretend play. Our analysis indicates that participatory sense-making plays a key role in the success of pretend play sessions. We use the cognitive science theory of enaction as a theoretical lens to analyze the empirical data given its robust conceptual framework for describing participatory sensemaking. We present here five enactive characteristics of pretend play that appear to be necessary and sufficient for the emergence and maintenance of successful pretend play -mental preparation, meaning building, narrative enaction, narrative deepening, and flow maintenance. This enactive formalization is used to propose a computational model of pretend play that can be used to inform the design of an agent capable of playing in real time with human users.