Starring Vince Vaughn and Owen Wilson. Rated 14A.

There's not really a lot to Wedding Crashers. What you see in the trailers is pretty much what you get: two charming hustlers conning their way, usually with elaborately specious back stories, into ritzy nuptial celebrations, the better to glom onto booze and food, not to mention females in a heightened emotional state. Fortunately, the crashers in question are played by Vince Vaughn and Owen Wilson, doing what they do best, and their infectious charm keeps the party going most, if not quite all, of its amiable two hours.

Vaughn plays Jeremy, the pushier of two successful divorce lawyers-a professional irony not mentioned after the film's start-while Wilson's laid-back John is the follower whose fun is slightly clouded by misgivings, and even the odd bout of erectile dysfunction. Things get complicated when they tackle, at one last ceremony of the summer, a New England bash for one of three daughters of the current secretary of the treasury, played by Christopher Walken. (The film is set in a fictional United States, with cabinet secretaries that have real power.)

There's a hitch for both boys, pretending to be brothers, when the secretary's youngest daughter (Isla Fisher) gets hung up on Jeremy-he calls her "a Stage Five clinger"-and John is smitten by the middle girl, Claire (The Notebook's Rachel McAdams at her most appealing). The rest of the tale is about resolving these conflicts, which also include Claire's fiancé (Bradley Cooper), whom the filmmakers burden with far more douchebaggery than is strictly necessary, considering that our sympathies are already with John. There are some funny bits with Jane Seymour as Claire's Mrs. Robinson-like mom, but we could have lived without the portrayal of her neurotic brother (Keir O'Donnell), which is tainted by such old-school homophobia that younger audiences might be baffled by its mood-killing strangeness.

Another deficit is director David Dobkin's saving of a certain Big Name Actor to spring on us near the end as Jeremy's wedding-crashing mentor-a pointless stunt that only serves to undermine the cleverness of the script (by Steve Faber and Bob Fisher) when it's clicking. Any tale in which a smarmy bachelor seduces a bridesmaid by promising her "poetry, courtesy of Miss Sarah MacLachlan" doesn't really need stunts. I would like to know, however, how Vaughn manages to eat all those crab cakes and blintzes without getting fat.