Drillbit Taylor (12A)

Seth Rogen, Heigl's co-star in Knocked Up, keeps writing screen versions of himself, and they're getting younger by the picture. In Superbad, Jonah Hill played a tubby, curly-haired teen about to start college. Now, in Drillbit Taylor, Troy Gentile plays a tubby, curly-haired adolescent about to start high school. We must presume that the next Rogen screenplay will feature a tubby, curly-haired five-year-old about to start infant school. Soon we'll be able to view his whole career on a wall chart of diminishing Rogens, like a picture of evolution in reverse.

Like the others, Drillbit Taylor revolves around a trio of friends. Whereas in Superbad they're trying to get laid, here they're trying to avoid getting bullied, a plan that goes awry on the very first day when beanpole Wade (Nate Hartley) and Ryan (Troy Gentile) turn up wearing exactly the same shirt. Aargh! Soon enough, their gaffe attracts the chief bully (Alex Frost), who bundles them up in one shirt and calls them "the Siamese queers". Even the headmaster chuckles at that. The boys, battened on by a hobbitty loner named Emmit (David Dorfman) – "He's like a stray cat; once you feed him he'll never go away" – decide that the best way to survive school is to hire a bodyguard.

Of all their applicants, the only one they can afford is Drillbit Taylor (Owen Wilson), who claims to have been trained in special-ops before being discharged from the army for "unauthorised heroism". He holds out his arm and crooks his elbow. "Know what this is?" he asks the boys. "It's a wing – and you're under it." They hire him immediately, though what they don't know is that he actually deserted the army and now lives as a dumpster-haunting vagrant. The silliness of the conceit is complicated by its juvenile fantasy of protection. As the boys veer between their everyday ordeal and the possibility that their "bodyguard" might save them, one can't help wonder how closely Rogen has based their terror of bullying on his own experiences – it's an oddly fearful kind of comedy for an adult to write. He is fast becoming the laureate of adolescent misfits.

Watch the trailer for 'Drillbit Taylor'

A slide into mawkishness is threatened but mainly avoided by the vigour of the young cast. The boys play off one another like a junior version of The Three Stooges, and their interaction with Wilson is amusingly done. The latter barely strays from type as the sleepy-eyed charmer who's not all he seems. I'm not quite sure how he manages to pass himself off as a substitute teacher at the high school, still less how he so quickly secures the affections of Leslie Mann's English teacher – he introduces himself as "Dr Illbit" – but you can't help enjoying his stumblebum improvisation and the lies that mount up around him. When the boys finally twig that he's not a trained bodyguard, one of them asks him if his name really is Drillbit. No, he admits with a sigh, it's actually... "Alamo" Taylor.