In this paper we examine the role of play in human ontogeny and phylogeny, following Surplus Resource Theory. We consider how juveniles use play to sample their environment in order to develop adaptive behaviors. We speculate about how innovative behaviors developed in play in response to environmental novelty may influence subsequent evolutionary processes. Play during this period of immaturity is especially important in the processes of development and evolution, because in play new strategies and behaviors can be developed with minimal costs and these strategies, in turn, can influence evolutionary processes. We posit that play influences these processes by supporting the development of new strategies in novel environments during the juvenile period.