The VR-0 is an underground fighting automaton built by the Void Ring Collective — a loose network of automaton engineers, fight promoters, and combat sport fanatics who operate entirely outside legal channels. Unlike the mass-produced Dogfighter, each Phantom Limb is hand-built and unique, assembled from salvaged military and industrial components into a fighting machine that reflects its builder's philosophy about combat. Some are fast and evasive, some are heavy grapplers, some are pure strikers. No two fight alike.

Phantom Limb units are status symbols in the underground fighting world. Owning one means having connections to the Void Ring Collective, which means having access to the deepest layer of the illegal automaton scene. The machines are entered into tournaments against each other and against human fighters in events that move between cities, never using the same venue twice. Human-vs-Phantom Limb fights are the headline events — five-round bouts where the human fighter's purse increases each round they survive, with a massive bonus for a knockout or technical stoppage of the machine.

The Collective maintains a ranking system for both Phantom Limb units and human fighters, tracked on an encrypted network accessible only through invitation. The top-ranked human fighters — people who have consistently survived or defeated Phantom Limb opponents — are celebrities in the underground world and utterly unknown to the public. They walk through normal life with broken hands and scar tissue and reputations that exist only in whispers.