'Wimpy Kid: Rodrick Rules': Oh, brother!

 There are good kids and bad kids in the movies, but rarely ones in between. It's as if Hollywood can't admit that children can be selfish, cowardly and cruel, even while remaining essentially decent. One question: Aren't any of the studio heads parents?

"Diary of a Wimpy Kid: Rodrick Rules," the second adaptation of Jeff Kinney's illustrated novels, once again embraces the nice and the nasty in its young characters. Zachary Gordon and Devon Bostick return as Greg Heffley and his surly teenage brother, Rodrick, whose relationship has only worsened since last year's movie. Fed up, the naive Heffley parents (Rachael Harris and Steve Zahn) leave the brothers alone for a weekend to "bond," perhaps hoping to come home to Beaver and Wally Cleaver.

That doesn't happen. Rodrick throws a party and locks Greg in the basement; Greg blackmails his way out. They do bond -- by lying to their parents. And the detente they develop is easily shattered.

Many colorful kids from the first film return, notably the unsinkably nerdy Rowley (Robert Capron), along with a new seventh-grade dream girl, Holly Hills (Peyton List). That makes for a scattered script, but it's saved by Gordon and Bostick (still pitch-perfect as a fledgling punk wearing Mom's eyeliner), who have settled into their roles and reveal a genuine rapport.

"You may be my brother," Rodrick tells Greg, "but you'll never be my friend." Later, of course, there will be an affectionate shoulder punch. "Rodrick Rules" is the rare kids' film that can deliver both blows with conviction.