"Walking" robots (stompbots) propelled by means other than wheels were initially given a 50% weight bonus. The rules changed following the victory of a heavyweight stompbot (Son of Whyachi) at BattleBots 3.0. For BattleBots 4.0 and beyond only a 20% weight bonus was given to walkers and the technical rules specified that walking mechanisms do not use cam operated walking mechanisms as they were functionally too similar to wheel operation. Since the rules change, walking robots have entered the competition, but none has achieved any success beyond preliminary rounds. As of 2020, true walkers are given a 100% weight bonus, allowing the only competing walker, Chomp, to weigh 500 pounds.
