Step Brothers is a 2008 slapstick buddy-comedy film directed by Adam McKay, produced by Judd Apatow and Jimmy Miller, and stars Will Ferrell and John C. Reilly, who last teamed up in Talladega Nights (2006). The screenplay was written by Ferrell and McKay, from a story written by Ferrell, McKay and Reilly. The film was released theatrically on July 25, 2008, and on DVD and Blu-Ray on December 2, 2008.

Plot

Brennan Huff (Ferrell) is an unemployed 39-year-old who lives with his divorced mother, Nancy (Mary Steenburgen). Dale Doback (Reilly) is an unemployed 40-year-old who lives with his widower father, Robert (Richard Jenkins). Robert and Nancy get married and move in together, forcing Brennan and Dale to live with each other as step brothers; their childish dislike for each other is immediate.

Dale warns Brennan not to touch his drum set, but Brennan does so anyway. As tensions escalate, Brennan rubs his testicles (described by Ferrell in the DVD audio commentary as "$25,000 of prosthetic balls") over Dale's drums. This ignites a huge fight, in which Dale and Brennan use weapons such as headphones, bicycles, and bare hands to attack each other. In response, their parents declare that their sons must find jobs and see therapists or else be forced out of the house. Brennan's successful, conceited biological younger brother Derek (Adam Scott) comes to visit with his oddly perfect family (who nearly cause a car accident as they sing an a cappella rendition of "Sweet Child o' Mine" on the drive over). Dale retreats to his tree house where he and Brennan read pornography. Derek drops by to mock them, and incites Dale to punch Derek in the face. Brennan is awed by the fact that Dale was able to stand up to Derek. Brennan's sister-in-law, Alice (Kathryn Hahn), meanwhile, finds Dale's courage arousing, and becomes infatuated with him. Brennan and Dale become best friends.