This paper constructs a new framework for the study of games as sites of social rationalization, applying Feenberg's critical theory of technology. We begin by making the case for a consideration of games as systems of social rationality, akin to other modern systems such as capitalist markets and bureaucratic organizations. We then present a conceptualization of play as a process through which the player focuses attention away from the undifferentiated action of everyday life toward a differentiated sphere of playful activity. This approach reveals how the experience of play changes as it becomes rationalized through the technological mediation and widespread standardization that occurs as games become large-scale social practices. We propose a theory of the rationalization of play (ludification), which outlines the key components of socially rationalized games, which we then apply to the specific example of MMOGs.