Computer games represent a vast economic market, a key driver of technology, and an increasingly powerful medium for a broad range of applications. The latest wave of innovation for computer games is ‘mobile’ and more precisely, ‘location-based’. These outdoor mobile experiences are radically different from traditional computer games or their mobile equivalent. Player's attention is focused on the real world as much as on the digital world of the game, aiming to create a powerful juxtaposition of the two.