Identity Disc

Identity Discs are the most fundamental piece of equipment to programs in both the Game Grid and in the Tron system. They contain all that a program is, in the form of a detachable glowing disc normally worn on the upper back. Everything seen, heard, or otherwise experienced is recorded on the disc.

Digitized users have often been issued with an identity disc shortly after arrival inside the system. Although a human being is a far more complex entity than a basic program, they still appear to need the device during prolonged stays when digitized. The discs of users can perform all of the same operations as for programs. Aside from its primary function as a receptacle of a digital entity's entire being, the identity disc is also a weapon. When energized they have a lethal cutting edge that can derezz an opponent instantly with a direct hit. This damaging capability can be applied in very close quarters where the disc can be used as a short bladed weapon, and also as a buckler shield.

The primary combat application however is as a thrown weapon. In this capacity the disc is hurled at a target, and may ricochet off unyielding surfaces, before returning directly to its owner. Skilled users can even curve a disc in a shallow arc to avoid striking things blocking the line of sight to a target beyond. The leading edge of an identity disc does not harm its owner when caught, even when travelling at very high speeds.

Tron
The Original identity discs in the Game Grid appeared as a solid disc of their owner's color, with several glowing concentric rings on the surface. The disks have lipped edges, resembling frisbees. An identity disk can also be used hold liquid energy and drink from it like a cup.

Tron: Legacy
The appearance of an identity disc is of a solid ring with a glowing inner edge. The color of the inner edge matches the circuitry color of its owner. The outer edge, when energized, becomes a brilliantly glowing nimbus of white light with a slight tint of the owner's circuitry color

Quotes
When given an Identity Disc, the recipient is told, "You will receive an Identity Disc. Everything you do or learn will be imprinted on this disc. If you lose your disc or fail to follow commands, you will be subject to immediate deresolution." This line appears in each movie; It is spoken by Sark in TRON, and by the female Grid announcer's voice in TRON: Legacy.

Trivia

 * When Kevin's son Sam escapes the TRON system with Quorra, he copies data from the Grid onto a computer chip that resembles an early generation disc.