The old Japanese robot cartoons of the late seventies and early eighties generally abide by these implicit rules.
- Earth (or the galaxy in a few cases) is threatened by an evil force, usually an alien monarchy.
- The ruler of the evil empire has got to destroy or enslave humanity. And to do so, he has a faction of loyal subordinates who are willing to die (in fact they do), to fulfill their superior's plans.
- Earth (or its parallel) is attacked by one of the evil subordinates who bred/built a giant monster/robot to terminate all human opposition.
- A group of scientists realize humanity could be facing the end of its days, so they decide it's time to try this "experiment" they have been working on since their fourth semester in MIT (or its Japanese equivalent).
- The experiment results to be a giant humanoid robot that is proportionally equal in size to the evil monster/robot and the only way to control it is to pilot the mecha from a "control booth" in its head. The only exception I know of this is Iron Man 28 (also known as Gigantor).
- The only suitable person who could take up the job of operating the giant robot and fight against the evilmonsters/robots is a teenager who knows little or nothing of the existence of the mecha until a surprising event lead him to the group of scientists.
- The teenager is a skinny rebel with a weird dark hairdo who is, as a previous w/u exposed, emotionally disturbed. Generally by some sad or obscure event that may or may not be related to the creation of the giant robot he is about to pilot and/or the evil forces he will encounter.
- A team made up of some other teenagers, generally some of the pilot's friends, is assembled to help him with the "extra" parts of the robot, assisting with information, weaponry and such.
- There would be a girl in the team, who in some cases assists the scientists (and could be a close relative of one of them). Whenever pilot and girl meet, discussion is ensued. Of course we know they like each other, but when war and violence are spread, there is little time for love.
- No matter how experienced the alien subordinates can be, they are always defeated by teenager, who has no experience whatsoever in close quarters combat, even less in operating heavy machinery.
- Despite the utter failure, The evil alien forces don't give up and keep sending more giant aliens/monsters one at a time (maybe they don't understand the concept of teamwork).
- The evil alien monarchy keeps coming up with stronger monsters/robots and more evil plans, but somehow, the mecha always truimphs.