Episode list

The US Championship followed a similar format to the Grand Finals of the regular UK version of Robot Wars, beginning with two first-round 'Eliminators' between the four competing robots. Winners of each battle would progress to the final to determine the US Champion, preceded by a playoff (referred to as the Bonus Battle) determining third and fourth places.

Two teams, each with two robots, entered the arena at once. Only one member from each team was allowed to battle at any one time. If a robot wished to let its team-mate into the action, it was to return to its CPZ. There, the robots could switch out and tag. However, these rules were very frequently broken and battles often featured all four robots battling at once. The tournament featured four teams; two American and two British. The first two battles were qualifiers to decide which team would go through to the final to represent their respective country. There was also a playoff for third place between the heats and final.

The competition worked similarly to the Mayhem fights in Robot Wars Extreme, with three robots fighting each other at once. Unlike the latter, where winners would qualify for one of the Annihilators, the three winners of each Nickelodeon Mayhem would advance to a final three-way battle known as the Ultimate Mayhem, which was shown as the main event of Episode 5. Whichever robot won the final round would be declared the Mayhem Champion.

An 'open call' for teams to settle old scores against their competitors.

One robot is given the belt and defends it against challengers in one-on-one combat. Three successful defenses in a row win the tournament.

Five robots fight simultaneously in a 'melee' battle. One robot is eliminated and the melee restarts with the remaining four. The process repeats until only the annihilator champion remains.