Haddish, Hart earn mixed grades in ‘Night School’

This image released by Universal Pictures shows Kevin Hart in a scene from "Night School." (AP)

Malcolm D. Lee’s “Night School” brings together the potent combo of Kevin Hart and Tiffany Haddish, but this tepid if amiable sitcom-stretched-into-a-movie elicits widely differing grades for its two comic powerhouses.

Energetic as it is, Hart’s hyper shtick has grown tired from overuse, while Haddish’s fresher powers appear limitless. Both are good enough — and good enough together — to keep “Night School” from flunking out; this is a decent enough placeholder in between (hopefully) bolder efforts from each.

But it doesn’t help that Lee, who made Haddish a revelation in last year’s “Girl’s Trip,” casts her as effectively the straight man. Haddish, Hart and a classroom should be all that’s really needed for a laugh-filled comedy. But a thin script (by Hart and five other writers) doesn’t give either enough material, nor does keeping Haddish slightly under wraps as a taskmaster teacher in an adult education class.

Hart stars as Teddy Walker, a successful Atlanta patio furniture salesman who — as seen in the flashback prologue — skipped out on the SATs and never graduated high school. When his lavish proposal to this girlfriend, Lisa (Megalyn Echikunwoke), goes explosively awry in the store he works, Walker’s tenuous lifestyle — a sports car and downtown condo to give Lisa the impression he’s wealthier than he is — comes apart at the seams.

Teddy’s only hope for employment beyond a Christian Chicken fast-food joint is with the financial company of his friend (Ben Schwartz), but for that he needs his G.E.D. For night classes, Teddy returns to the high school of his youth, which is now run by his teenage rival (Taran Killam, as a racist and pitiful principal). His teacher, Carrie (Haddish), has no patience for Teddy’s usual circumventions and eventually — sit down for the shock — gets him to study.

“Night School” is at its best in its classroom setting thanks to a freewheeling ensemble adeptly juggled by Lee. Too much of “Night School” is coated in redemption schmaltz (Hart’s story line) or is missing Haddish (Hart’s story line). But the night school scenes, while still a little tame (the film is rated PG-13 when the freedom of an R rating seems required), pingpong animatedly between a misfit group of G.E.D.-seekers.

Best of the bunch are Al Madrigal (as a Mexican immigrant waiter who Teddy, trying to avoid a steep bill, got fired) and Romany Malco (“The 40-Year-Old Virgin”), as the class’ most off-kilter participant (He considers “The Terminator” to be “prophecy.”). But also good are Mary Lynn Rajskub, as a mom fleeing her kids, and Rob Riggle, as an earnest but oafish student. Fat Joe, as a convict, also joins by Skype from prison. There is at least a promising sitcom in there.

Yet the teaming up of Haddish and Hart goes down as a missed opportunity. Though she makes Carrie easily the film’s most human character, Haddish isn’t given enough room to let loose; “Night School” is really Hart’s film. And, like countless studio comedies of the past few years, “Night School” is a straightforward concept that relies too much on the charisma of its performers to carry a weak script. It didn’t do its homework.

“Night School,” a Universal Pictures release, is rated PG-13 by the Motion Picture Association of America for crude and sexual content throughout, some drug references and violence. Running time: 111 minutes. Two stars out of four.