The “Easy A” might as well be for a class in astronomy. This is supposed to be the movie in which the redhead it girl Emma Stone (“Superbad,” “Zombieland”) is born as a star. If dying stars turn into black holes, sucking everything around them into eternal darkness, then movie stardom defies the laws of physics.

Stone absorbs the surrounding creative matter, burns it into a ray of light and shoots it across space and time. If this were a political science class, I would say she transforms each scene, and eventually the whole movie, into a referendum upon her. And that is how a star is born.

Astronomy aside, “Easy A” thinks of itself as an English class. This teenage sex comedy studies at the school of filmmaking that snatches classic high school literature and resets it in high school. For better or worse, that’s how Shakespeare becomes “10 Things I Hate About You,” all so the kids can relate. Director Will Gluck and writer Bert V. Royal choose that all-too-mandatory Nathaniel Hawthorne novel The Scarlett Letter. The smart-girl-gone-wild Stone even stitches the letter A on her suddenly spicy wardrobe.

That takes us to drama class. Heretofore invisible understudy Olive Prenderghast (Stone) rises to the role of school floozy after a false rumor spreads around school. She becomes an actress, creating the illusion of a convention-challenging sex life that doesn’t exist. Like any great thespian she lures other students into her evanescent performance, pretending to have sex with school outcasts–such as her gay friend (Dan Byrd)–so they can win social acceptance. Hester Prynne-like, she accepts shame so that others can live freely.

As in many schools, there’s always the risk of plagiarism, but really it’s more allusion and talking about your favorites. Royal’s script mentions John Hughes by name, and Gluck throws in an energetic musical number referencing Matthew Broderick’s famous singalong in “Ferris Bueller’s Day.” Otherwise, the verbose snark at times reminds of “Juno.” A snotty Christian student (Amanda Bynes) brings a bit of “Mean Girls” or “Heathers.”

It might be more sensible to grade “Easy A” with a pass-fail system. It is very attentive one minute and looking out the window the next. Why create delicate differences in rating its success? Everybody gets what they expect, and everybody gets the point.