MANILA, Philippines??21,? a movie about college kids who rake in money from casinos by figuring out a way to beat the system, is more entertaining to watch when you?ve only got half your brain turned on.

However, if you?ve gone through the trouble of finding out what the movie?s about before going to the ticket booth, you?re probably going to walk into the cinema with some expectations. After all, ?21? is a movie about smart people who use math to beat the supposedly unbeatable casinos at their own game. So, it?s not unreasonable to expect the film to be smart, as well.

Predictable

But, while the movie is easy to watch?it?s paced briskly, has engaging leads and a glossy, finished feel?it doesn?t offer much that?s new. The plot is predictable, the characters are generally one-dimensional, and the gritty details, which could have been the movie?s saving grace, are few.

It?s a shame, really, since the tale itself is interesting. The film is loosely based on the book, ?Bringing Down the House: The Inside Story of Six MIT Students Who Took Vegas for Millions,? by Ben Mezrich. Touted as nonfiction by its author, various facts laid out in the book have turned out to be not so factual and, apparently, several scenes didn?t happen at all.

At least, this much is true: There was indeed a group of card counters?students and alumni of the Massachusetts Institute of Technology (MIT) and Harvard University?who developed card-counting techniques and other strategies to beat casinos at blackjack, not just in Vegas, but throughout the world.

Card counting, which is a strategy that skilled players use to determine whether they have a probability advantage, is completely legal. It?s all done in the head, after all. Casinos don?t like it, unsurprisingly enough, and tend to get aggressive when they find out about it. However, audiences won?t come away with card-counting tips after they watch the movie, so casinos have nothing to worry about.

Though the movie does go into detail regarding the system used, it shies away from a more in-depth view. It?s a bit strange, actually, since it?s the story?s raison d?être. Director Robert Luketic (?Legally Blonde?) and scriptwriters, Peter Steinfeld and Alan Loeb, probably thought the math would bore audiences?but in truth, the tired Hollywood devices they used to pad the film with are more mind-boggling.

Medical school

The film has a conventionally structured plot: A brilliant student (Jim Sturgess, earlier seen in ?The Other Boleyn Girl? and ?Across the Universe?) who initially just wants to earn enough money for medical school, joins a team of card-counters headed by a professor (Kevin Spacey being Kevin Spacey).

He is seduced by the big wins and bright lights of Vegas, abandons his friends, is betrayed by the snarky professor, runs afoul of the casinos (represented by Lawrence Fishburne, being old-school with his fists), avenges himself and makes up with his friends.

It?s a sequence of events we?ve seen many times before, and everything?including the love interest (a dry Kate Bosworth)?is so predictable it would have been completely uninteresting if not for Sturgess? unexpectedly nuanced performance. It?s one of the few surprises in a movie that could have been outstanding, but is content to be just average.