Contestants can be either self-contained, tethered, or radio controlled.
Last one still in the ring wins. Robots must attempt to push each other off the edge of a 6ft round platform, but they can be more aggressive about it. If a tie is declared, the winner will be based upon perceived aggressiveness. The initial dimensions of all robotic competitors must fit within the boundaries of a 1 foot cube. Once the trial has begun, however, the machine may expand its dimensions as required, so long as it does not extend past the edge of the competition ring.