Plot:
Danny (Paul Rudd) and Wheeler (Seann William Scott) are two energy drink salesmen who promote a drink called "Minotaur" to school children, and encourage kids to stay off drugs. Wheeler loves the job, but Danny hates it, viewing it as a mindless, dead-end job. Danny's pessimism results in the collapse of his relationship with lawyer Beth Jones (Elizabeth Banks), after he impulsively proposes to her. After one presentation the duo find that their Minotaur truck is being towed, as they were parked in a no-parking zone. They try driving the truck away from the tow truck, damaging the tow truck, nearly running over a security guard (Louis C.K.) and crashing into a statue. They are arrested as a result.
Beth strikes a deal with the judge in which they have to log 150 hours of community service over the next 30 days, in lieu of 30 days in jail. The judge selects for their community service a big-brother style program called Sturdy Wings, led by Gayle Sweeny (Jane Lynch), a recovering addict. Gayle instantly dislikes the two and warns them that if they fail to carry out their tasks she will have them imprisoned. Wheeler is paired up with Ronnie Shields (Bobb'e J. Thompson), a foul-mouthed streetwise miscreant obsessed with breasts, who has driven away all the other "Bigs" he has been paired with, while Danny is assigned Augie Farcques (Christopher Mintz-Plasse), a nerdy teenager obsessed with medieval live action role-playing games.
Danny is unable to find common ground with Augie. Ronnie takes virtually no interest in Wheeler. Danny considers choosing the jail sentence, but Wheeler insists that if they go to jail, they will get raped, which Wheeler is strongly against. They gradually bond with their "littles". Ronnie takes an interest in Wheeler's favorite band, Kiss, and discovers that Wheeler shares his obsession with breasts, and Wheeler teaches Ronnie to control his obsession with breasts. Danny and Augie bond when they realize that they are both involved in the Sturdy Wings program against their will, and as a result Danny joins Augie's live action role playing game, "LAIRE" (Live Action Interactive Role-playing Explorers). Despite their successes, Danny attempts to reconcile with Beth, but to no avail (Beth must commit to the break-up, stating that it is for the best).
However, their success is cut short. When Augie manages to sneak up on the King of LAIRE, Argotron (Ken Jeong), the King lies and tells everyone that he killed Augie. Danny, backing up Augie, shoves the King, and gets himself and Augie banned from LAIRE forever. Later, Danny insults Augie's mother and stepfather for refusing to support Augie's hobby, earning their animosity. As soon as Augie's parents kick Danny out of their house, Danny quips back, "I'd be psyched if he were my kid." Meanwhile, Wheeler takes Ronnie to a party and leaves him unsupervised, resulting in Ronnie walking home alone and a series of angry messages from his mom on Wheeler's cell-phone. Ronnie and Augie's parents ask Sturdy Wings for new mentors, and Danny and Wheeler are removed from the Sturdy Wings program, thus failing to complete their community service. Beth says that she will defend Danny and Wheeler in court, but cannot make any promises, as they will eventually be sent to jail. Danny and Wheeler argue and go their separate ways.
Danny convinces King Argotron to allow himself and Augie to fight that afternoon in the much-awaited Battle Royale. Wheeler gets permission from Ronnie's mother to hang out with Ronnie after he gets out of jail, and earns Ronnie's forgiveness. However, the King secretly warns the other members of Augie's LAIRE "country" of Xanthia that allowing Augie to fight with them will lead to severe retribution in the game. They call Augie to tell him he's too much of a liability and he has nowhere to turn. To form a new LAIRE country, Danny and Augie need four members and matching costumes. Danny asks Wheeler and Ronnie to join them. They arrive with Wheeler's KISS costumes and a Kiss-themed Minotaur truck, naming their new country "Kiss-My-Anthia". After a betrayal by his former Xanthian allies, Augie finally duels with the king, defeating him. A hidden player, Sarah (Allie Stamler), who goes by Esplen in LAIRE, then attacks and defeats Augie; she is crowned the new queen and chooses Augie as her king-consort. Augie's parents forgive Danny.
Impressed with having seen that Wheeler and Danny do care for the children and not simply themselves, Sweeny clears their names with the judge. Danny serenades Beth with a rendition of the KISS song "Beth" and they finally reconcile.