Don’t believe the hype on Wedding Crashers, at least not the part proclaiming it a festival of crazy, raunchy, inappropriate behavior that will revive the dying R-rated comedy.

It’s strongly characterized, extremely funny and very entertaining, albeit a little long and labored in its final 20 minutes. But it’s far more conventional and, cue the falling fist of a pumped-up frat boy on summer break, kind of a chick flick.

Naturally, the R-rated Wedding Crashers has teeth that a PG-13 version of the same material would not. But those looking for skin are better served flipping through Playboy, and those seeking bodily-function jokes can feel free to cue up the fondue scene in Meet the Fockers. This movie is, at heart, a well-mannered and well-meaning look at the errors of the ways of two aging Lotharios.

John (Owen Wilson) and Jeremy (Vince Vaughn) are two smooth-talking divorce mediators in D.C., suave sportsmen who look forward to “the season” — the wedding season, that is. For the last 12 years, John and Jeremy have honed the art of crashing weddings, in which they schmooze with little girls and elderly relatives and fake sensitivity to bed misty-eyed bridesmaids and guests.

Only John questions the dying thrill of the hunt. Still, he’s rejuvenated when Jeremy suggests crashing the Cleary nuptials. Jeremy dubs it “the Kentucky Derby of weddings,” as the bride’s father is Secretary of the Treasury William Cleary (Christopher Walken).

John quickly falls for the bride’s sister, Claire (Rachel McAdams, instantly likeable). Meanwhile, Jeremy sleeps with another sister, Gloria (Isla Fisher, who proves herself a wired-up comedienne), only to find she’s a “stage-five clinger.”

Hoping to pursue Claire, John accepts Gloria’s invitation to spend the weekend with the Clearys (while a frightened Jeremy looks on). What they don’t know is that the Clearys are like the Kennedys on an increased diet of booze and aphrodisiacs. It says something that Walken plays a comparatively normal member of this family of sexually sadistic miscreants.

Vaughn earns the R-rating in nearly all of his scenes. Extended farcical bits at a dinner table and in a bedroom (where Jeremy suffers one hellish night of seduction troubles) register the best. And this is the actor at his comedic finest; not only does he return to the motor-mouthed delivery of Trent from Swingers, this easily could be Trent 10 years later. (The movie also draws laughs from inspired ideas such as John and Jeremy wagering on Bible-passage readings and the idiotic tough-guy speech of over-privileged WASP males.)

The weirdness of the Cleary family piles up at the right moments. But the movie also remembers that there’s a real person hidden among them, too — making questionable decisions about her life partly because she thinks it’s a way to keep the family together.

It’s the best possible irony that the summer’s strongest female character shows up in a movie about two womanizing players. McAdams now has delivered a one-two punch of star power (along with The Notebook), and it would be a crime for her to not become the next great actress. In her performance, it’s easy to see how Wilson becomes an infatuated fool for her. Wilson also plays well a role usually reserved for his brother Luke.

In trying to be humorously juvenile and responsibly grown-up in less than two hours, Wedding Crashers does go through some awkward phases — a last-act raid on an engagement party could be cut entirely and the narrative passage of time is too long. But Wedding Crashers wisely favors sophistication over shock value. How you feel about that depends on the open-mindedness of your own inner child.