Fifty million dollars for this? With one slipshod and highly forgettable performance -- possibly the worst of her career -- Cameron Diaz becomes the highest paid actress of all time. Funny how that works.

What Happens in Vegas is a decidedly average romantic comedy that achieves nothing new and regurgitates well-worn cliches. And even what it rehashes -- particularly plot elements we've seen time and time again -- is done half-heartedly.

The film is about a couple with zero shared history, both from the Big Apple, who live markedly different lives until fate -- as it always seems to -- brings them together.

Joy (Cameron Diaz [Images]) trades stocks on the 'floor' in Wall Street and lives in the heart of Manhattan, a life as high-stress and high-stakes as they come. Jack (Ashton Kutcher [Images]), in contrast, is a lackadaisical carpenter, who works for his overbearing father, shacks up in a Brooklyn bachelor pad and is told by random sexual partners that he's not 'serious boyfriend/husband material'.

The ball gets rolling when Joy, eager to please her hotshot, corporate bigwig fiancee, plans a surprise party for his birthday. Unfortunately, he has other plans, and she gets a very public axing before guests can even jump from the closet and yell 'Surprise!' For good measure, he throws in some embarrassingly explicit details about their sex life and asks her to permanently leave his flat.

Jack, after disappointing his perfection-seeking father time and time again, is given an ultimatum: win a one on one basketball game against the old man or find a new job. In typical underachieving fashion, he falls short, quitting before Pops hits the final shot.

So both Joy and Jack have reason to get away, and they independently escape to that oasis of hedonism in the Nevada desert: Las Vegas [Images].

They meet as the result of outrageous circumstance. And a long night of alcohol-fuelled revelry follows, ending with one of those infamous Las Vegas weddings, though both parties have only blurry recollections come morning. Still nursing hangovers, they agree to part ways, laughing at the outrageousness of their temporary union, when fate intervenes once more, and the two find themselves the joint recipients of a $3 million jackpot.

From there, impossible odds and ridiculous coincidence give way to downright falsity, as the two are forced by a judge's decision to stay married for six months before the cash is theirs. Of course, a judge could never render such a ludicrous decision, but that doesn't stop What Happens in Vegas from its flight of fancy.

In the end, the film tells us that Diaz takes life too seriously and tries too hard, while Kutcher takes things easy and doesn't try at all. When their forces combine, however, they both achieve happiness through a kind of yin-yang symbiosis. Yawn.

Kutcher, of Punk'd and That 70's Show notoriety, delivers his ubiquitous performance: a kinda dumb, kinda lovable fool with good looks and a sense of humour. In other words, it's his umpteenth rendition of Kelso.

Cameron Diaz has aged, albeit gracefully, but she fails to impress and doesn't sparkle like in There's Something About Mary and Being John Malkovich.   

They do share a certain degree of onscreen chemistry, particularly when at each others' throats. But the film constantly tries to balance sophomoric potty humour (Jack pees in the sink when Joy won't relinquish the toilet) and sickeningly cloying sentimentality (There's a romantic beach scene replete with lighthouses). It ends up bogged down by both.

To be fair, there are moments of humour. It's just that they're rare and hardly of the gut busting variety.

Of the supporting actors, props must go to Kutcher's father (Treat Williams), who competently plays the overbearing but loving dad.

Jack's friend cum lawyer Steve Hader (Rob Corddry) is supposed to provide comic relief, but fails, coming off shrill and annoying. So too does Diaz's bartender friend, Tipper (Lake Bell), who's constantly and with no good reason at Hader's throat.

An overdose of Kutcher's trademark, tired humour makes the film more cheesy sitcom than blockbuster, though worldwide box office results say otherwise, for reasons I cannot begin to fathom.

Even the ghastly lighting and sets seem lifted straight from a television pilot that didn't quite make the cut. The music is unremarkable. Special shame should be reserved for the cheesy, stomach turning dialogue, which inspires far more groans than giggles and makes every character a two-dimensional caricature.

New York City is a daunting environment in which to film a movie, but the Big Apple eventually serves as a lone bright spot. Whether it's the basketball game played in front of a Manhattan skyline backdrop or the narrow, working class alleys of Brooklyn, Tom Vaughan manages to translate some of New York's particular charm through the big screen.

But finding positives is like scouring the proverbial haystack for a lone needle. Or, better yet, like hitting a $3 million jackpot on a lowly Vegas slot machine.

Rediff Rating: