Three separate arrangements of modular playground assemblies may be constructed from identically shaped support members and one of three different crossbars. Playground equipment such as a platform member, a slide member and swing devices can be attached to the basic assemblies. The support member is preferably a unitary, molded plastic member, having openings therethrough to serve as steps and an access opening to accommodate climbing and other play by children using the assemblies. The basic components can be selectively combined into units for distribution and use in making one of the three assemblies.