Tron Identity Disk

Identity discs issued to Game Grid programs appear as solid discs with several concentric rings on the surface, glowing with their owners' circuitry color. The circuits glow more brightly when the disc is in use, and have been seen to change size or flash on and off when active. In flight, old-system discs appear as uniform circular planes of light in their owners' circuitry color, trailing comet-like tails as they fly towards their targets. Despite this appearance, they are still solid to one another, and ricochet from other discs with an audible clank.