Ben Mezrich's book "Bringing Down the House" became a best-seller because of its true story -- MIT whiz kids who used a card-counting system to beat the Vegas casinos for millions -- told with the energy and smooth intrigue of fiction.

It might have made for a good movie "¦ but then Queen Latifah and Steve Martin stole the title for their 2003 comedy and everything was downhill from there.

Filmmakers eventually decided that truth wasn't going to be good enough, and "21" was born: a generic version merely "inspired by" the goings-on of the book.

Young British actor Jim Sturgess ("Across the Universe") stars as Ben Campbell, a shy but brilliant MIT student who lacks the enormous amount of money needed for Harvard Med school; the kind of money an $8 an hour job won't cover.

Fortunately -- or unfortunately -- he is pulled into a moneymaking scheme masterminded by a charismatic professor (Kevin Spacey). The strategy is simply devised, but can only be carried out by a crew of nimble numbers-crunchers like those found in virtually every MIT dorm room.

Card counting at blackjack isn't actually illegal, but it is frowned upon by the casinos, making secrecy important and lending an aura of danger to the process. Certain casinos, after all, will do more than just ban offenders from the premises.

With the MIT crew, Ben transforms into a slick high roller who discards his old friends and ways in favor of thrills, women and money.

"21" is interesting for a while, and by and large, the performances are very good. Sturgess is an actor with a future, sort of a nifty Tobey Maguire-Jake Gyllenhaal combo. Kate Bosworth ("Superman Returns") is suitably sultry as Jill, a partner in crime and possible love interest. Spacey, who also produces, chews up scenery (in a good way) as the professor. And Laurence Fishburne appears to be having fun as the team's nemesis, a well-dressed casino thug.

One fun piece of trivia: Jeff Ma, the unnamed star of the book (he was called Kevin Lewis there), has a cameo in the movie as a blackjack dealer.

I honestly can't blame the filmmakers for spicing up the non-fictional story -- card counting and blackjack are not inherently cinematic, and the book's virtues are hard to translate to the screen. The way they changed it, however, leaves something to be desired. Some generic twists and turns are tossed in, but they pale in comparison to, say, an "Ocean's Eleven."

"21" never goes bust, but it doesn't draw a blackjack either. More of a 17, with the dealer showing a face card.

Rental recommendation: William H. Macy is perfect in "The Cooler," a guy hired so his bad luck will rub off on high-rolling gamblers. Grade: A-.

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