Romantic comedies seldom veer far from the tried and true formula that makes the genre what it is: boy meets girl, boy and girl feel an attraction, boy loses girl, boy gets girl back. New romantic comedy “What Happens in Vegas” isn’t an exception to these rules, but what it does do, it does well.

Cameron Diaz and Ashton Kutcher are Joy McNally and Jack Fuller, two very different New Yorkers who both happen to find themselves down on their luck. In an effort to turn things around, they gather their respective best friends and go to Las Vegas for a night of drunken debauchery. It is in Vegas that Joy and Jack meet, get very drunk, and wake up to find themselves married. The bickering starts almost immediately and the pair decides to get a divorce as soon as they return to New York. There’s just one problem: before leaving Vegas, Jack hits the three million dollar jackpot and, as his wife, Joy is legally entitled to half of it.

Back in New York, Judge Whopper (Dennis Miller) denies Joy and Jack a divorce, instead freezing the money and sentencing the two to six months of marriage, during which time they must prove that they are trying to make their marriage work. What ensues is a series of (surprisingly) funny moments as Joy and Jack try to make life miserable for one another, succeeding in many ways while also learning a bit about themselves.

“What Happens in Vegas” is predictable and formulaic. The emotional scenes feel fake and phoned in, at best. Diaz and Kutcher merely reprise the roles they’ve had in every other romantic comedy they’ve ever done, and at times are annoyingly unbelievable as the characters they portray.

Regardless, the film is not without its bright moments. Supporting actors Rob Corddry (as Jack’s friend Hater) and Lake Bell (as Joy’s friend Tipper) really steal the show. Their incessant arguing is hilarious and perfectly timed. The cameo appearances by Dennis Miller and Queen Latifah are also pitch perfect.

“What Happens in Vegas” is one of those unfortunate films where you can predict the ending after five minutes of viewing. Even so, it’s still worth watching for the lighthearted laughs it provides.