Will Ferrell and John C. Reilly are comic powder kegs in this slap-happy, hilarious romp. They're a pair of goof-offs who become family when one's mother marries the other's father, and soon bad blood flows and sparks fly between the two contentious and competitive guys. Mary Steenburgen and Richard Jenkins portray the parents. Ferrell, who cowrote the script, and Reilly costarred in "Talledega Nights," which was directed by Adam McKay, who also directs this comedy.