What is the difference between the ways children play and adults play? Children's play often appears to be non-goal-directed, or at least involves a certain mutability of rules and goals. Adult play appears to be more formalized, goal-directed, and rule-following. It may be that the types of intelligent systems that we develop for the purposes of creating fun experiences must do completely different things depending on whether the AI system is playing with adults or playing with children. Interestingly, improvisational theater might be a middle-ground where some of the rules, and indeed the entire fictional world, can be changed and redefined.