Tabletop displays are gaining interests in gaming environments. Computer Game in the genre of board games, competitive actions, real-time strategies are amongst those that are suitable for tabletop displays. Currently most games developed for tabletops use physical objects with markings as the controllers and standard touch and gestures as the inputs. To extend the present limits of gestures and touch, we present an implementation of high performance sensor-based input modality as an extension to tabletop displays. The additional input modality has the capability to sense and track users’ bodies while they are interacting with the table. This paper outlines the configuration of the sensors, the tracking accuracy test result and informal evaluations of the system. We emphasise the simplicity of sensor configuration, cost, robustness and high performance in the design of tabletop sensor systems. To demonstrate the capability of our system, we developed a computer game ‘‘Body Pong’’ where each player controls a paddle assigned automatically to him/her by moving his/her position left and right. The game demonstrates how contextawareness adapts when number of users changes during game play.