Matrix training is a generative instructional approach where stimulus pairings are taught with the goal of emergent responses occurring without direct instruction. The 4x4 matrix in this study was comprised of 16 characteraction pairs (e.g., princess sleeping, prince climbing) taught and tested in the context of play. The researcher trained peers without disabilities to provide instructions and feedback to three children with autism spectrum disorder (ASD) for four character-action pairings. In the context of a multiple baseline across participants design, results showed that untrained responses for the remaining character-action pairings emerged in 73% to 100% of opportunities across participants. In addition, responses for all participants occurred with novel peer trainers. For two of the three participants, responses also were demonstrated during independent play probes. Results of this study suggest that matrix training mediated by a peer can be an effective and efficient method for teaching play skills.