"Now you see that Evil will always triumph, because Good Is Dumb."Why do heroes always act like idiots, even when not Idiot Heroes? They always make the worst decisions when the time comes. Sure The Good Guys Always Win and end up Saving the World from the Big Bad, but they seem to have an aversion to making smart choices while doing it. Oh, that's right, they're holding the Hero Ball. This is the hero-specific form of the Idiot Ball, which causes its holder to make downright moronic decisions solely because the plot demands it. Unlike the Villain Ball, the Hero Ball almost never leads to its holder's permanent defeat; it merely delays the hero's inevitable victory, ratcheting up the dramatic tension in the meantime (at least, until the Fridge Logic kicks in). Of course, once victory is assured, the Hero Ball will prevent its holder from killing or permanently incapacitating the villain — after all, the villain needs to be back on his feet in time for the next episode. If he carries the Hero Ball long enough, one almost gets the impression that the hero is more interested in padding the plot than in actually defeating the Big Bad. This can be particularly frustrating when we've been shown (or at least told) that the hero should be smarter than this.
—Dark Helmet, Spaceballs
Heroes who are likely to carry the Hero Ball
Plot and devices resulting from the Hero Ball