What college mathematical whiz kid wouldn't take the bait to make a fortune in Las Vegas if assured he could get away with it -- especially when he desperately needs cash to pay for Harvard med school?

Like Oscar Wilde, earnest Ben Campbell can resist anything but temptation in the highly entertaining "21," a true-life adventure based on Ben Mezrich's bestselling book, "Bringing Down the House."

Mezrich's subtitle serves as handy synopsis: "The Inside Story of Six MIT Students Who Took Vegas for Millions."

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'21'

3 stars = Good
Ratings explained

• Starring: Jim Sturgess, Kevin Spacey, Kate Bosworth.
• Rating: PG-13 for some violence and sexual content containing partial nudity.
• Web site: sonypictures.com/movies/21

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Shy, honest Ben (Jim Sturgess) is the last of the dirty half-dozen MIT "mathletes" recruited for a secret blackjack club that uses card-counting et al numerical skills to beat the dealer. His main recruiter was sexy blonde Jill (Kate Bosworth), but their ringleader is MIT's distinguished, charismatic nonlinear equations professor Micky Rosa -- aka Kevin Spacey.

"We're not gambling, we're counting cards," he tells his proteges, laying down strict rules of engagement and conduct before leading them on a high-rolling "working junket" to Nevada, armed with "foolproof" signals, disguises and a whole new language, whose words are numbers and whose numbers are words.

The master is prickly, however. "Dude, I lost track 20 cards ago!" says one of the kids during a rehearsal. "Don't call me dude," growls Micky.

But he's a great teacher, and the students are great learners. With success, once-timid Ben gets cockier and cockier, little realizing that in Vegas, greed -- not speed -- kills. Eventually, he will run afoul of Micky, who long ago ran afoul of casino security boss Laurence Fishburne. The latter has a score to settle.

Sturgess and Bosworth are engaging, with a sexy love scene or two late in the picture. Aaron Yoo, Liza Lapira and Jacob Pitts do equally well as their fellow scam-gang members, while Spacey is a delicious villain.

Director Robert Luketic provides nice pacing and slick production values for the screenplay by Peter Steinfeld and Allan Loeb, which contains some hokiness -- notably, the obligatory subplot of Ben letting down his friends in robotics class, plus an unlikely final rematch between Ben and his Svengali.

Other problem: I thought I understood blackjack. (Pardon my name-dropping, but I was given tips by Tony Curtis at Caesar's Palace.)

The intricate counting-scheme system here, however, despite the filmmakers' noble attempts at explanation, remained an impenetrable mystery to me. Maybe you'll do better.

In any case, these appealing young grifters and their movie are more satisfying than many another Vegas flick, including "Ocean's 12, 13" -- all the way to 21.