Field and McKee were obsessed with the theoretical underpinnings of storytelling. But Snyder’s book is far more straightforward. And that’s why it’s conquered the big screen so thoroughly. Indeed, if you’re on the lookout, you can find Snyder’s beats, in the order he prescribes, executed more or less as Snyder instructs, in virtually every major release in theaters today. Even the master storytellers at Pixar stick quite close to Snyder’s playbook: Watching Monsters University this summer, I loved the way it toyed with underdog sports and college movie conventions. Yet the story hits every one of Snyder’s beats, including an opening image that’s mirrored in the final scene, an act break when Mike and Sully reluctantly join forces to compete in the Scare Games, a false victory about three-quarters of the way through when (spoiler!) they “win” the final Scare Games challenge, and an all-is-lost moment followed by an emotionally charged dark night of the soul next to a moonlit lake afterward.

Yet once you know the formula, the seams begin to show. Movies all start to seem the same, and many scenes start to feel forced and arbitrary, like screenplay Mad Libs. Why does Kirk get dressed down for irresponsibility by Admiral Pike early in Star Trek Into Darkness? Because someone had to deliver the theme to the main character. Why does Gina Carano’s sidekick character defect to the villain’s team for no reason whatsoever almost exactly three-quarters of the way through Fast & Furious 6? Because it’s the all-is-lost moment, so everything needs to be in shambles for the heroes. Why does Gerard Butler’s character in Olympus Has Fallen suddenly call his wife after a climactic failed White House assault three-quarters of the way through? Because the second act always ends with a quiet moment of reflection—the dark night of the soul.

And if the villain of the past few years of movies is the adolescent male for whom it seems all big-Hollywood product is engineered, Snyder’s guidelines have helped that bad guy close the door to other potential audiences. Save the Cat! doesn’t go so far as to require that protagonists be men. But the book does tell aspiring screenwriters to stick to stories about the young, because that’s “the crowd that shows up for movies.”