Most children are able to successfully develop and use social skills in the context of interactions with peers and significant adults. Moreover, the ability to interact successfully with peers is crucial in establishing and maintaining viable social relationships. For children with disabilities, like pervasive development disorder (PDD), development of these skills is difficult. Children with PDD often demonstrate deficits in foundational social-communicative behaviors such as joint attention and imitation, and they frequently lack the motivation to engage in social reciprocity. Children with PDD often exhibit deficits in social communication behaviors that adversely impact later language development. One way to uncover areas of strengths and weaknesses is within the context of play. Play offers a way of engaging children because the goals of play are often flexible, self-imposed, and can change over the course of time. In play with others, children are required to act in socially appropriate ways to extend and enhance the play interaction. Extending play interaction requires a set of socially communicative signs that signal a willingness to interact with another, along with the necessary skills to sustain the interaction. However, because children with PDD often demonstrate less global and detailed play skills, it is difficult to uncover foundational skills that can be built upon to enhance larger repertoires of behavior. Simple guidelines that caregivers can follow to uncover the prerequisite skills for later complex play behavior are needed. In this article, the authors describe the three specific prerequisite skills (social referencing, reciprocity, and initiation/responding) that are critical to the development of complex play behavior, and then discuss interventions that caregivers can easily implement to target each skill.