Code of Combat

The Cybertron Code of Combat is an aspect of Transformer culture and law that governs personal combat between the leaders of two factions with the loser being exiled into deep space forever.

The code requires a warrior to fight as they are without any form of enhancement or aid from their comrades.

Generation 1 cartoon continuity
After Megatron took all the powers of his fellow Decepticons, he engaged in personal combat against Optimus Prime, who did not know that Megatron had far more abilities then he normally had, with the loser being exiled from Earth.