While most robot masters are build with Asimov's "Three laws", as well as a few directives to dictate their actions, Dr. Wily's robots are built with no laws, and three "Wily Directives". Two oddities to that rule being Bass, who's directive to destroy Mega Man was on top, making it take priority over obedience, and Zero, who's brain was too complicated to be shackled by any directive, anyways.