PONG is a basic simulation of the racket sport of table tennis. A small square representing a ping pong ball travels across the screen in a linear trajectory. If the square strikes the perimeter of the playing field, or one of the simulated paddles, the square ricochets based on the angle of the impact. Game play consists of players moving their respective paddles vertically to defend their scoring zones. Players score one point by maneuvering the square past their opponent's paddle. PONG can be played either by a single player pitted against a computerized opponent, or by two players each controlling a paddle. In Atari's original PONG arcade cabinets, players controlled their paddles using one of two small paddle controllers (a knob-like input device). Contrastingly, several of the derivative table tennis simulations employed longitudinally-sliding joysticks.

Should be here in the near future.