Endearing underdog hero Greg Heffley returns for another year of middle-school humiliation in “Diary of a Wimpy Kid: Rodrick Rules,” capitalizing on the sleeper success of the 2010 kidpic before puberty has a chance to render runt-sized Zachary Gordon any less wimpy. Quickie adaptation of Jeff Kinney’s second novel — which centers on big brother Rodrick’s ongoing torture of the seventh-grade weakling — blends “Brady Bunch”-style morality with other standard-issue sitcom tropes, then redeems itself via memorable supporting characters. It’s hardly Harry Potter, but even without wizards or vampires, Fox clearly has a healthy young-adult franchise on its hands.
The remarkable thing about the original “Wimpy Kid” was the fact that it didn’t take the lazy route of manufacturing a nemesis for its titular outcast, but instead allowed Greg to learn from his own mistakes, the way real adolescents inevitably must, even if it meant recognizing its self-absorbed hero as something of a jerk. This much safer follow-up feels far less subversive, falling back on stock coming-of-age devices, including bully Rodrick (Devon Bostick), out-of-his-league love interest Holly (Peyton List) and a school talent show where everything comes to a head.
With the exception of Chloe Moretz, busy making “Hugo Cabret” with Martin Scorsese, all the key players are back, which makes for nice continuity as “Wimpy Kid” opens at the start of a new school year, with a retro roller-skating party for incoming seventh graders. True to Kinney’s books, screenwriters Gabe Sachs and Jeff Judah recognize that nothing is more intimidating to today’s teens than the prospect of public embarrassment, a fear they exploit by repeatedly putting Greg in situations where he risks widespread ridicule: wearing Speedos to swim practice, being babied by his parents in front of Holly, getting trapped outdoors in nothing but his underwear, and so on.
Adolescence is humiliating enough without someone actively tormenting you, but Greg has it especially rough, with Rodrick dreaming up creative pranks to antagonize his brother. (Equally crafty younger sibling Manny, played by twins Owen and Connor Fielding, takes a backseat in this chapter of the series.)
Greg’s well-meaning mother (Rachael Harris) and mostly clueless father (Steve Zahn, barely tapping his comedic potential) try to remedy the situation by forcing their sons to spend quality time together. While the parents are away, the boys throw an illicit house party — a ridiculously PG-appropriate affair characterized by soda chugging and conga lines — that results in some genuine bonding before Greg spills the beans.
In the lead, Gordon has the wide-eyed appeal of a young Matthew Broderick: He looks nothing like Kinney’s crudely rendered cartoon character, but makes the mischievous character likable even when his often-inconsiderate actions invite reproach. It’s thanks to Gordon that younger auds can identify with the character while “Wimpy Kid” soft-sells the sort of behavioral lessons parents appreciate.
Pic’s animation demands are minimal, an artifact of the story’s first-person diary device, allowing “Astro Boy” helmer David Bowers to demonstrate his live-action chops. He gets mostly solid perfs from his young ensemble, though the characters feel more two-dimensional this time around, clearly doomed to sitcom-style supporting status in this and future installments. Bostick is just silly enough to sell the goofily rebellious Rodrick, while List looks pretty as the otherwise personality-bereft blonde, Holly.
Since production values are only modestly better than TV, Fox might as well rush to adapt the rest of Kinney’s “Wimpy Kid” series while the cast is still scrawny enough to fit the bill.