The last three weeks of school life have begun: After the Abitur, Germany's leaving certificate, the friends and schoolmates of Gymnasium Kerkheim (Kerkheim High) will not see each other again so soon. It is a hard time for Markus and his girl Sandra from a lower grade, as he wants to hang out with his old friends, whereas she wants him to be there for her. It's an even harder time for Dirk, who is to be expelled from school if he fails the math exam that is coming up around midday, and it is the hardest time for Michael, who is a perfect pupil, but has no fun in life at all - and doesn't even know it yet. When Steven calls out a party to celebrate his letter of exemption from the army, they all get together for one of the last real cool events ever.
A school teacher discusses types of government with his class. His students find it too boring to repeatedly go over national socialism and believe that dictatorship cannot be established in modern Germany. He starts an experiment to show how easily the masses can become manipulated.
The story's protagonist, Peter LaFleur (Vince Vaughn), is a charismatic underachiever and proprietor of a rundown gym called Average Joe's. The facility's clientele of decidedly less-than-"average Joes" is made up of a self-styled pirate, a scrawny nerd who dreams of impressing an unattainable cheerleader, an obsessive aficionado of obscure sports, a dim-witted young man, and a cocky know-it-all who, of course, really knows nothing.
Peter's humble gym catches the eye of White Goodman (Ben Stiller), the power-mullet-sporting, Fu-Manchu-d, egomaniacal owner of Globo Gym, a gleaming monolith of fitness. White intends to take over Average Joe's, and Peter's non-existent bookkeeping is making it all too easy for him. A foreclosing bank has stationed attorney Kate Veatch (Christine Taylor) inside Average Joe's to finalize Globo's takeover of the gym. But Peter's boyish charms win her over and Kate joins his team of social rejects to beat the odds - and their own ineptitude - to try to save Average Joe's. How? A showdown dodgeball competition against Globo Gym.