Based on a true story, 21 features swindles in modern times, using pretty young things and the lascivious backdrop of Las Vegas to tell its story of card-counters and the windfalls they so easily acquire. The technique is technically legal, and at least one of the participants is playing just so he can send himself to med school. Therefore, Robert Luketic’s film is in theory both sexy and relatively sinless, a bootstrap-pulling tale wrapped in fun, fun, fun. The reality isn’t nearly as brutal as what happens to counters when they get caught—the strategy may not be illegal, but casinos do frown upon it—but it will still be a disappointment for moviegoers who prefer their escapist entertainment to be less, well, utterly inert.

Most of the film’s vanilla flavor comes from the cast, led by British white boy Jim Sturgess (Across the Universe), whose Ben Campbell is the cinematic representation of the story’s real-world card-counter, Asian-American Jeff Ma, and lifeless Barbie Kate Bosworth as Ben’s requisite love interest. Ben is the Harvard Med-head whose math professor, the ridiculously named Micky Rosa (Kevin Spacey), recruits him for MIT’s super-secret blackjack team when he notices the student’s skill with numbers. Ben agrees, but only because he “can’t believe” that the only thing keeping him from furthering his education is money—how cute is that? After a training period involving flash cards, code words, and a rapid-fire addition/subtraction deck system, the gang is off to test their wits in the gambling capital of the world.

Back when Ben is still mulling the offer over, Bosworth’s Jill coos to him, “You should feel the thrill of winning more money than you could possibly imagine.” Well, so should the audience. But instead Luketic treats us to Ben’s thoughts as he’s playing, complete with flashbacks back to the flash cards lest we forgot that a partner’s mention of a “magazine” really means something else. The scheme is too dense for nonprofessionals to grasp, which means most viewers will simply tune out any time the characters spend at the tables. And when they’re not winning, they’re montaging. Here’s the happy bunch whooping it up at a strip club—which, ridiculously, thanks to the film’s PG-13 rating, features clothed dancers. Here they are going shopping. Now Ben is back in his dorm room, jumping on his bed after stashing his cash in the ceiling.

Scripters Peter Steinfeld and Allan Loeb, adapting a book by Ben Mezrich, try to inject some emotion into the story, giving Ben not only a girlfriend but also best buds whose group nerd project he must abandon when his weekends become dominated by trips West. The problem is that none of these characters are interesting: Ben and Jill have the dullest hookup imaginable, for instance, and in general, everyone is personality- and humor-free. Spacey can’t even spice things up, only embarrassing himself when he borrows a little of his Glengarry Glen Ross vitriol to deliver some similar but woefully subpar dressing-down lines. It all feels like a cheat.