Evidence which suggests that pretend activities become increasingly independent of the presence of realistic objects is examined in this paper. Results of research on pretend behavior in children 1 1/2 - 2 years of age are described and analyzed. Striking changes in pretend behavior are shown to occur during the second year of life. Pretend play is treated as a paradigm for understanding how children represent objects and relations. It is argued that the child can pretend that one thing is another when he can represent objects (or object activities) as prototypes and when he can use the core properties of prototypes to transform representations of immediate physical stimulation. The analysis suggests a three-phase sequence in the development of pretending based on a progression from the analogue mapping of representations to the selection and, eventually, the production of the core properties of object representations. (Author/ED)