
Sometimes, it's used as an excellent piece of Schmuck Bait to lure someone into a trap by making it Forbidden Fruit tell someone not to press it, list all the negative side effects it will cause and all the terrible consequences if they do press it, and you can almost guarantee they will press it. (At least the only one that's not painted on the background layer.) In animation, this will often be the only control, period. In live action, this will often be the only control big enough to make out on camera. Pressing the Big Red Button activates the function of a given machine that is important to the plot, be it firing the superweapon, activating the Self-Destruct Mechanism, or emergency shutdown.

It's usually colored red, as a hazard warning. The activation control of choice for any truly powerful weapon or effect, usually located dead center on the control console, sometimes under a molly-guard.
