The authors' overarching research strategy involved two major components: the identification of strategic treatment targets and the assessment and cultivation of available resources for treatment. The RPT used peers as treatment agents and used play as a context for the enhancement of preschoolers' social effectiveness. Resilient peers were children who functioned exceptionally well even though they faced the same set of environmental stressors as the target children. The first in a series of three studies was a small-scale pilot study designed to assess the effectiveness of the RPT strategy for socially withdrawn, maltreated preschoolers. The second study was designed to replicate the previous pilot study on a larger scale with the use of more rigorous experimental procedures and to assess the relative effects of using a resilient peer or a familiar adult as a treatment agent. The third study was designed to determine if these peer and adult treatments would have a similar effect on different populations of socially ineffective, maltreated preschool children. The different response patterns of the withdrawn and aggressive maltreated children to the peer and adult play partners suggest that the RPT strategy is effective for withdrawn maltreated children, but is ineffective in its present form in the treatment of aggressive, maltreated children. 3 figures and 23 references