Universal Pictures

"Role Models" stars (from left) Christopher Mintz-Plasse, Paul Rudd, Seann William Scott and Bobb'e J. Thompson.

The premise is formulaic and potentially cheesy: A couple of go-nowhere buddies get arrested and, for their community work assignment, must serve as big brothers to a pair of misfit kids.

You know from the beginning that many necessary life lessons will be learned and that all parties involved ultimately will be better off for the unlikely friendships they have formed. Whittled down to 30 minutes, this could have been a very special episode of "Diff'rent Strokes." But it's the wildly, hilariously crude way that director David Wain and company approach this concept that makes "Role Models" so disarming.

The rampant wrongness would have been amusing enough on the page: preadolescents spewing obscenities, jokes about bad touching and children being exposed to nudity on a supposedly wholesome camping trip. But the delivery from co-stars Seann William Scott, Paul Rudd and the supporting cast of both comedy veterans and up-and-comers makes the material consistently laugh-out-loud funny.

Wain, who directed "Wet Hot American Summer" and "The Ten," reunites with several members of the defunct MTV sketch comedy show "The State," including Ken Marino, Joe Lo Truglio and Kerry Kenney-Silver, and there's a comfort in the familiarity of the weirdness.

Wain and Rudd are among a half-dozen people who get screenplay or story-by credit here. Scott and Rudd are at the film's core, though, and their disparate styles provide an appealing mix; Scott again plays the manic ladies' man with no internal censor, while the typically deadpan Rudd is always ready with a sardonic one-liner.

Scott's Wheeler and Rudd's Danny spend their days giving peppy, just-say-no talks at Los Angeles schools and peddling the energy drink Minotaur. Danny, fed up with his life and frustrated that his longtime girlfriend (Elizabeth Banks) has just rejected his marriage proposal, snaps one day and gets himself and Wheeler in trouble with the law. (Banks, who has shown versatility with "W." and "Zack and Miri Make a Porno," goes to waste here as the straight woman.)

Rather than going to jail, the two end up working with the Sturdy Wings mentoring group, led by the damaged but overly earnest Gayle (Jane Lynch, stealing every scene she's in, as usual): "I used to be addicted to pills," she explains in one of her many cringe-inducing lines. "Now, I'm addicted to helping."

Wheeler gets paired up with the freakishly foul-mouthed Ronnie (Bobb'e J. Thompson, radiating a scary amount of confidence for a 12-year-old), who's been raised by a single mom. No previous big brother has stuck around for more than a day, but rather than feeling daunted, Wheeler views Ronnie as a personal challenge.

Danny, meanwhile, gets stuck with the uber-dweeby Augie (Christopher Mintz-Plasse), who's obsessed with his live-action fantasy role-playing game. Augie is part of Sturdy Wings at his parents' insistence: They want him to be a normal kid.

This is the kind of movie in which an adult and a child can bond over the not-so-subtle metaphor contained within the song "Love Gun." Inappropriate? For sure. But also kind of sweet -- and a model for comedies that are trying to strike that elusive balance.