Noting that children's play activities, particularly the development of dramatic scenarios, have been a central focus of developmental-interaction thinking over many decades, this paper explores the emphasis on play and the specific meanings accorded to it within this developmental-interaction tradition. The first part of the paper considers the views of play held by the tradition's founders--Harriet Johnson, Caroline Pratt, and Lucy Sprague Mitchell--and how this view was realized in practice. The second part examines writings by Biber and her associates that attempt to integrate the original lines of thinking with psychodynamic formulations. The introduction of psychoanalytic theory impinged on, and changed concepts of, play process and medium, sources of material, and the functions of play. The third section argues that certain contemporary developments in psychological theorizing provide new grounding for central ideas about play in classic developmental interaction. These are: articulation of symbolic mediation theory, as represented in the work of Werner and Kaplan (1983/1963) and Vygotsky (1986); a broadened view of cognitive functioning, in particular the idea of narrative as a fundamental way of organizing experience (Brockmeier and Harre, 1997; Bruner, 1986; Wells, 1986); and the theme of self developing in interaction with others, specifically peers, in social collaborative activity. (Contains 52 references.) (EV)