At Faber College in 1962, there is a conservative air about the campus, embodied by the Omega fraternity, which accepts what it deems to be the best and the brightest, but isn't very accepting of anyone else, including two potential pledges, Larry Kroger (TOM HULCE) and Kent Dorfman (STEPHEN FURST), a "wimp and a blimp," according to Babs, a name-tag hostess at the Omega house.
Larry and Kent arrive at Delta house, and Kent convinces Larry it'll be easy to get in, because his brother, Fred, was a member and according to him, legacies have to be admitted. This fraternity is the polar opposite of Omega: Rowdy, bawdy, and always home to the heaviest drinkers on campus. Beer is always available, beer bottles are thrown around, and occasionally, a mannequin is thrown out of the second-floor window.
The anarchic nature of this fraternity is what causes the college's Dean, Vernon Wormer (JOHN VERNON), the most consternation. What good is this college in being conservative if all of its student body doesn't abide by that? With such students as the wild John 'Bluto' Blutarsky (JOHN BELUSHI), the ladies' man Eric 'Otter' Stratton (TIM MATHESON) and jokester Donald 'Boon' Schoenstein (PETER RIEGERT), Wormer sees much reason to find a way to expel all of them. Accordingly, he employs members of the Omega fraternity to try to do so, and it's the right fit, because Omega hates Delta as passionately as Wormer does.