ARmy: A study of multi-user interaction in spatially augmented games

We present ARmy, a two-player military strategy game that uses spatially augmented reality to combine physical tabletop games with the virtual elements and computation characteristic of modern video games. As players move plastic miniatures within a small scale physical environment, the application moderates and augments play by maintaining a 3D representation of the scene, which it uses to validate movement paths and perform automatic line-of-sight calculations for combat. We describe the design and implementation of the ARmy gaming system. Furthermore, we conducted a user study to gauge the effectiveness, in-tuitiveness, and robustness of the application. We describe the process of this user study, present quantitative data of the study results, and discuss general design principles for the design and implementation of other engaging spatially-augmented games.