Okay, so maybe this one isn't totally the fault of Hollywood. The three-act structure has been around for a long, long time. It originates in theatre, which is why it has act in the name you never saw act breaks in a Hollywood movie, did you? but it's in cinema that it found its real home. The three-act structure is the most basic framework on which to base a screenplay, the litmus test which ensures your story will be up to the usual standards of a blockbuster. We aren't kidding when we say it's incredibly basic: the three acts in question are the Set Up (that's the first third of the film; everyone gets introduced, as does the central conflict that drives the plot), then Confrontation (the conflict comes to a head; bad guys and good guys both fight to get the upper hand), followed by Resolution (the climactic scene of the conflict, followed by a satisfying ending). Once you know the three-act structure, you can apply it to any story you're told, whether it's in a movie, video game, book, or your mate down the pub on a Friday night. It also means that, since everything and everyone uses that structure, stories get incredibly predictable. Anyone who's seen a handful of films knows roughly when the Set Up is over, realises that when it seems like the villain has the upper hand halfway through it won't last, and can judge how long there is left of a film once the climax has clearly been reached. Thanks a lot, the theatre.