In the original Mega Man series, a Robot Master is a nickname for the bosses from the Stage Select Screen, which usually are humanoid robots that possesses a very advanced level of artificial intelligence, and in some media it is a term for similar robots such as Mega Man. Most Robot Masters possess a unique identification code, consisting of a two-letter "series code" followed by one of N, No, or #, then a three-digit "serial number". Most, if not all, Robot Masters possess a Special Weapon that can be gained after the robot is defeated.