Computer game technology produces compelling “ immersive environments” where our digitally-native youth play and explore. Players absorb visual, auditory and other signs and process these in real time, making rapid choices on how to move through the game-space to experience “meaningful play”. How can immersive environments be designed to elicit perception and understanding of signs? In this paper we explore game design and gameplay from a semiotic perspective, focusing on the creation of meaning for players as they play the game. We propose a theory of game design based on semiotics.