The Underground Robot Brawling Ring (or URB) is, as it's name implies, an esoteric fighting circuit that pits artificial robotic lifeforms against each other in organized combat. Founded and led by Benjamin "Motherloving" King, the URB gathers robots from Circuit Falls to Nekropolis to battle in (often fatal) underground fights for money and prizes. These fights are not sanctioned by The Bureau of Robotic Affairs and are considered cruel and unusual. Robots are often placed in these fights by their opportunistic or desperate inventors for quick money. But there are a notable number of robots who enter these fights on their own. Robots are often seriously injured or even killed in these fights.
The URB is believed to have connections to The Circuit Falls Connection.