Just like “Ferris Bueller’s Day Off,” the high school comedy “Easy A” has a random musical number with no real connection to the plot. There’s a lot of borrowing from other coming-of-age movies too, from “Say Anything” and “Sixteen Candles” to “Clueless” and even “Mean Girls.”

The theft pays off because of “Superbad” alum Emma Stone in a breakout role. Fast, funny and devoid of the plastic Hollywood glamour that defines so many in her age group, Stone could be the younger, prettier reincarnation of 80s-era John Cusack.

Stone plays Olive, an unnoticed high schooler who fibs about sleeping with a college guy to her pushy friend. The rumor spreads around school, and pretty soon everyone thinks she’s a floozy.

With the reputation already in place, Olive decides to help a few of her outcast pals improve their social standing, and only in exchange for gift certificates to Best Buy and the Home Depot! As the lies spread, the Christian kids up their self-righteous wrath game, and Olive, ever the independent spirit, dons a literal Scarlett Letter. The message flies over the heads of most everyone except teacher Thomas Haden Church. I guess reading is limited to tweets and texts these days.

Stone is hilarious as Olive, taking seemingly superfluous lines and making them the funniest and most endearing moments in the film. The way she lets a jingle in one of those singing birthday cards dig a hole in her brain is just one random gem, as is that “Ferris Bueller”-inspired routine.

The older cast shines too, with Patricia Clarkson and Stanley Tucci playing Olive’s supportive/kooky parents. They pepper the film with some golden one-liners, especially when interacting with Olive’s adopted younger brother.

Directed by Will Gluck (“Fired Up!”), “Easy A” misses here and there, and the way Olive is demonized at school sometimes plays like a plot from one of those 80s movies. Has anybody seen recent statistics on teen sexual activity?

Those points, however, seem inconsequential as the film raises more serious points on the sexist high school dynamic. As Olive’s reputation grows more notorious, she learns just how idiotic her generation’s culture of information-sharing has become. It’s a film that will hopefully make a teenager think twice before updating their Facebook status.

Through all this is the standout performance of Emma Stone, a role that would earn her an Oscar nomination in a less competitive year. Cross your fingers her career doesn’t crash and burn like Lindsay Lohan.

Grade: B+