Nickelodeon Movies is a studio with a wide range of tastes—or else it's in a constant state of identity crisis. It's responsible for Harriet the Spy but also Nacho Libre; both Lemony Snicket's A Series of Unfortunate Events and The Last Airbender. Nowhere is this branding problem more obvious than in Fun Size. Though the comedy presents itself as a fairly chaste teen romp, its sense of humor is at serious odds with its subject matter.

Victoria Justice's sweet and vulnerable Wren suggests Fun Size is meant for the adolescent female set, but the lowbrow humor proves the producers had a much younger crowd in mind—yet it's hard to imagine that grade-school kids will be much impressed by the Johnny Knoxville or Ana Gasteyer cameos. That strange bit of casting might be an attempt to woo parents, many of whom might blanch at the foul language, rampant groping and illicit behavior. The strongest performance is Chelsea Handler's, whose arch sarcasm transcends her role of rebounding widow—she knows she's in an awful movie and couldn't care less as long as the check clears.

The film unabashedly cribs from Adventures in Babysitting, but the journey, captured in a series of jerky shots with little skill or forethought, isn't half as interesting. Ambitious high-school senior Wren is stuck watching her weird little brother, Albert, on Halloween. Albert is a kind of malicious idiot savant of indeterminate age (5? a short 15?) who would really best be left missing. Recovering him means skipping out on a crush's house party (or does it?) and teaming up with two sexually awkward classmates who have access to a car.

It's easy to guess where the tonal disjoint happened: Director Josh Schwartz's résumé features Gossip Girl and The O.C., so sexual content crowds his wheelhouse. Screenwriter Max Werner's previous credits are episodes of The Colbert Report, and it's not hard to imagine that when  presented with a hacky assignment, he allowed himself a few flights of fancy. The best lines are given to Fuzzy, the cerebral convenience-store clerk, who also manages the best delivery. In a more capable movie, Fuzzy would be the underwritten character we'd want to see more of, but he remains overwritten and tiresome—just like the rest of Fun Size. PG-13.

Critic's Grade: D

SEE IT: Fun Size opens Friday at Cedar Hills, Eastport, Clackamas, Oak Grove, Pioneer Place, Bridgeport, City Center, Division, Evergreen Parkway, Hilltop, Sherwood, Tigard, Wilsonville.