Studies on laboratory rats (Rattus norvegicus) have revealed that experience with social play in the juvenile period is important for the development of improved social skills, an improvement that appears to be mediated by the prefrontal cortex. But there is much variation in both the frequency with which play occurs and in the complexity of the actions performed among different strains of rats. Is all this variation adaptive in serving play’s critical developmental role? The integrative approach advocated by Tinbergen provides a framework with which to assess such variation. A review of what is known and the inclusion of some novel data suggest that irrespective of the form of the play, rats of all strains converge on the same key experiences, experiences that have been implicated in the development of social skills. The lessons learnt from rats may serve as a guide for broader cross-species comparisons.