Jim Sturgess, Jacob Pitts, Liza Lapira, Kate Bosworth and Kevin Spacey are shown in "21".

It would be easy to fall under the spell of "21" and get swept up in all the flashing lights, pretty girls and high stakes.

But, like a trip to Vegas, if you want to keep your wits, you have to realize that the real world works just a little differently.

"21" is based on the true story of a group of MIT students who formed a card-counting ring and "solved" blackjack. Like most true Hollywood stories, reality is probably much more interesting than the film we see.

But Hollywood wants to be Vegas, so it piles on the sizzle, leaving the steak a charred mess.

Ben Campbell (Jim Sturgess) is a brilliant but meek MIT student dreaming of attending Harvard Medical. He has a choice: Pony up $300,000, or most likely miss the school of his dreams.

A professor (Kevin Spacey) impressed by Ben's intelligence invites him to join his ring of students conspiring to beat Vegas at its own game: Learn a table's "count," play the odds and use hand signals and code words to win lots of money.

But Ben can't resist the thrill of the game. Or maybe it's the co-conspirator (Kate Bosworth) he's crushing on.

So the gang hits Vegas every weekend, employing disguises and assumed identities, and starts raking in the chips.

Soon Ben is seduced by the lavish lifestyle and mistakes make-believe for real life -- easy to do when there's 300 large behind your dorm room's ceiling tiles.

But no one told Ben that when you tango in Sin City, the devil is your dance partner.

Before long Ben catches the eye of the casino bosses, who employ an old school (read: brutal) loss prevention agent (Laurence Fishburne). Before long they catch on to the scheme, and they're none too pleased.

At this point the film unravels into a sort of junior "Ocean's 11," with intricate, implausible schemes and side bets and double-crosses, all under Fishburne's nose.

The subject matter is spectacular, but director Robert Luketic, working off of a screenplay by Allan Loeb and Peter Steinfeld, bobbles the romance arc and tries too hard to make Vegas a world filled with large, violent men who don't like to lose.

Ultimately "21" is like a couple of hours at a slot machine: pretty lights, some superficial excitement, but ultimately the house gets your money.

And, as Spacey points out, slots are for suckers.