The raunchy touches in “The Sitter” feel more obligatory than organic; the movie’s like an essentially good-natured kid at school who drops the f-bomb to keep up with his friends. But it does have a good nature, to its credit.

Landing somewhere between “Adventures in Babysitting” and “Halloween” in the subgenre of babysitter pictures, “The Sitter” recounts another bad night of minding the young ones. It also gives a lead role to perpetual sidekick Jonah Hill, who does his best with the uneven material.

Hill’s reliable delivery is perched in a sweet spot between innocence and hostility, which is just right for his couch-potato college dropout here. Pressed into service tending three kids at a neighbor’s house, he quickly gets them all involved in a disaster involving a cocaine buy, a stolen car and a jewelry store robbery.

The fact that the jewelry store belongs to his estranged father points to the source of the hostility. But he’s got hope, too; his self-centered object of desire (Ari Graynor) has just invited him to a party. Unfortunately, she also suggested the cocaine errand.

“The Sitter” has a peculiar vibe. It’s got little kids in it, and they sometimes bring the funny, but it’s also a foul-mouthed R-rated comedy, so it’s not remotely aimed at that age group.

Some of the gags attempt to be transgressive, especially where the kids are concerned, as though to explore a certain uneasy zone of creepy-funny. But it never really pushes too hard at that.

Director David Gordon Green, who did nicely with related material in “Pineapple Express,” understands where funny moments come from and he gets a few of them here. But this long night always feels like a bunch of screenwriter’s moments strung together.

It’s snappily done, and sly little jokes are waiting around the edges, and Sam Rockwell (as the coke dealer) goofs like a refugee from a Tarantino movie, waving his pistol around and asking for hugs. It’s not bad, as these things go, but nothing special, either.

If you’ve seen Jonah Hill lately offscreen, you know that he lost a dramatic amount of weight since this picture (and the earlier “Moneyball”) was completed. Will jokes that seemed funny from a chubby manchild sound as good coming from a slimmed-down version? We’ll see.

In the meantime, he’s still got the balance of wiseguy and innocent—the sort of dude who might initially mistake his girlfriend’s request to pick up some “coke” as referring to the caffeinated beverage in the red can.

“The Sitter” (2½ stars)

Jonah Hill plays a shiftless manchild put in charge of three wild kids for an evening, a resolutely R-rated experience that falls somewhere between “Adventures in Babysitting” and “Halloween” in the subgenre of babysitter films. Hill has some funny moments, although the movie overall feels like a string of half-done ideas.

Rated: R for language, subject matter.

Showing: Alderwood Mall, Cinebarre, Everett Stadium, Galaxy Monroe, Marysville, Stanwood, Metro, Oak Tree, Pacific Place, Woodinville, Cascade Mall.