The reputation of the British architect Cedric Price as a radical innovator within his discipline remains largely based on the Fun Palace project (ca. 1963–1965). Drawing on as yet unpublished archival material, this article explores the further development of Price’s work in the McAppy project (1973–1975). Therein he employed concepts drawn from systems theory and cybernetics in order to develop a user-oriented architecture. He interpreted the city as a social and built system that is continually being reshaped by the activities of its inhabitants, by artifacts, and by technologies. The aim of the McAppy project and many of his subsequent projects was to deploy organizational instruments and spatial interventions in order to offer opportunities such that people could shape their environment independently. Price expanded the discipline of architecture by introducing a new approach to design, which was based on viewing the city as a cultural product shaped by the interdependencies of its inhabitants and technical artifacts.