“What Happens in Vegas” leads to neo-screwball comedy in New York, and the result is an undemandingly diverting and exceptionally commercial pic that should click with its target 25-and-under demo, and probably woo respectable numbers of older ticketbuyers as well. Shrewdly positioned by Fox as counterprogramming to the early summer flash and filigree of “Iron Man” and “Speed Racer,” this two-seated star vehicle for top-billed Ashton Kutcher and Cameron Diaz wrings a respectable number of laughs from a formulaic scenario about attracted-opposites who bicker and back-stab their way toward happily-ever-aftering.
Some trend-conscious wags won’t be able to resist describing “Vegas” as Judd Apatow Lite, since it’s about a self-involved slacker who becomes more directed and/or responsible as a result of his relationship with a more mature woman. But, really, that set-up already had whiskers long before Apatow became a brand name.
In fact, the roots of this new pic can be traced back to screwball comedies of the ’30s and ’40s. The big difference — well, OK, one of several big differences — between “Vegas” and those fast-paced comedy classics is that “Vegas” actually becomes more enjoyable as it tamps down the over-the-top helter-skelter of its early scenes.
Dana Fox’s screenplay pivots on impulsive decisions by two dissimilar New Yorkers to vacation in Las Vegas. Jack Fuller (Kutcher), a party-hearty underachiever, takes this trip as a reward to himself after being fired by his father (Treat Williams) from a furniture-manufacturing job. Joy McNally (Diaz), a stressed-for-success commodities trader, flies to Sin City to salve her bruised ego after being dumped by her fiance (Jason Sudeikis) in earshot of other guests at his surprise birthday party.
Each character is accompanied by a best buddy — a second-rate lawyer (Rob Corddry) for Jack, a wisecracking cynic (Lake Bell) for Joy — but that doesn’t stop them ending a long evening’s drunken revelry with a spur-of-the-moment visit to a Vegas wedding chapel. Come the morning after, the regretful marrieds are ready to file for an annulment once they return home. But then Jack plays a slot machine with Joy’s quarter, and wins a $3 million jackpot.
Back in the big Apple, an acerbic judge (Dennis Miller) with conservative ideas about the sanctity of matrimony refuses to resolve the dispute over the $3 million jackpot, and challenges them to make the union work by sentencing them to “six months hard marriage,” with the first one who asks out losing the cash.
So ultra-organized Joy must move into Jack’s sloppy apartment. And the slackerish Jack must pretend to enjoy life with a woman who makes impossible demands, like putting down the toilet seat and not dumping his dirty laundry everywhere.
Naturally, each character tries to undermine the other, in the hope of ending the cohabitation and, more important, seizing the money. Just as naturally, the antagonists gradually warm to each other, pushed steadily closer as Joy charms members of Jack’s family, and Jack ingratiates himself to Joy’s boss (Dennis Farina).
There are no big surprises, and only a handful of unexpected developments. But Kutcher and Diaz are undeniably appealing as they go through familiar motions in custom-fitted roles, and the scene-stealing supporting players (Corddry, Bell, Farina and Queen Latifah as a marriage counselor) go about their petty larceny with amusing adroitness. Brit-born helmer Tom Vaughan (“Starter for 10”) tries too hard at first to emphasize free-wheeling zaniness, but settles into a smoother groove to keep this utterly disposable but lightly entertaining pic afloat.
Tech values are mostly unremarkable. Las Vegas scenes are conspicuously lacking in the snap and pizzazz auds have come to expect from interludes in the gambling mecca.