Rude, crude, and sometimes very funny.

Old School bases its humor on lots of profanity and sexual situations and doesn't bother with the logic of the story, sort of like a comedic Darkness Falls.

But unlike Darkness Falls, what Old School does, it does well. It's happy to be a goofy, cheerfully tasteless comedy about three 30-year-old buddies who have different ideas about growing up. Director Todd Phillips (Road Trip) respects the parchment-thin screenplay, which he co-wrote with Scot Armstrong, and works within its boundaries.

Luke Wilson plays Mitch, a lawyer whose settled life is sent spinning when a long-term relationship abruptly ends. He starts a new life, with the “help” of his buddies, the newlywed Frank (Will Ferrell) and two-time father Beanie (Vince Vaughn).

Beanie decides that Mitch needs a wild party to launch him back into bachelorhood. That Mitch doesn't necessarily want this is of no concern. Beanie wants it and therefore, Mitch must want it. He just doesn't know it.

The party celebrating Mitch's freedom incurs the wrath of Dean Pritchard (Jeremy Piven), head of Hamilton College, which owns the house that Mitch has rented. The dean gives Mitch two weeks to vacate, but the lease will let him to stay if the house's use can be linked to the college. No problem. Beanie decides to start a fraternity.

Now this fraternity will be one that has no purpose whatsoever except fun. “No community service or stuff like that,” Beanie tells potential pledges, who range in age from 17 to 90. Mitch doesn't like the idea, but he's swept into the tidal wave that is Beanie. As for Frank, his new marriage is on the rocks, thanks to aforementioned wild party.

One of the appealing things about Old School is that it seems to populate its story with stereotypes but really doesn't. Beanie turns out to be a devoted family man, and actor Vaughn, who has been in such intense films as Domestic Disturbance, Psy- cho, and Clay Pigeons, shows his flair for comedy.

Saturday Night Live's Ferrell plays Frank as a clueless 10-year-old who slowly gets a little wiser during the course of the film, only to discover that the world he had has gone on without him.

Wilson is perhaps the most stereotyped of all. He's fine at the beginning when he's floundering, but his decisive behavior at the end comes too easily for comfort.

And then there's Piven. A decade ago, he starred in the politically incorrect college comedy PCU, and to see him play the bureaucratic Dean Pritchard, bad hairpiece and all, is funny in and of itself.

The women don't fare as well, but really, they are in Old School simply to give the men someone to react to. Ellen Pompeo as Mitch's love interest, Juliette Lewis as Mitch's former lover, Leah Remini (The King of Queens) as Beanie's wife, Perrey Reeves as Frank's bride, and Elisha Cuthbert (24) as the daughter of Mitch's boss are attractive and, for the most part, interchangeable.

Old School will not go down as one of the great fraternity movies. It's not even in the same league as Animal House or Revenge of the Nerds. But those who can accept its overwhelming use of a certain socially unacceptable word and its sexually explicit but cheerfully rude humor will find a lot of fun.

Put another way, I was often horrified and embarrassed. But just as often, I was laughing like a fool.

First Published February 21, 2003, 1:30 p.m.