'Bad Teacher' won't make the honor roll

All legs and hair and eyeliner and attitude, Cameron Diaz makes a formidable bad teacher in the raunchy new comedy from director Jake Kasdan (Walk Hard: The Dewey Cox Story, Orange County). She’s nasty, conniving, and selfish as Elizabeth Halsey, a middleschool instructor who cares more about scamming money for breast implants than about student participation or test scores.

Diaz is funny, all right, but she is no miracle worker, so she can’t erase the movie’s slow spots or make it feel shorter than its 92-minute running time (it feels much, much longer, never a good sign for a comedy). Bad Teacher is as uneven as that wobbly desk you got stuck with in seventh grade. It’s amusing in plenty of spots but wastes too much time focusing on jokes that are repetitive and exaggerated (Lucy Punch as Miss Squirrel, the gung-ho, goody-two-shoes teacher determined to expose her rival as a drug-addled cheater) instead of rewarding better characters with more screen time (Jason Segal as a laid-back gym coach intrigued by Elizabeth is the film’s secret weapon, and he’s virtually invisible for the first half hour or so).

Cameron Diaz with co-star Justin Timberlake in the raunchy comedy 'Bad Teacher.'

As the film opens, Elizabeth is saying goodbye to the colleagues she despises at John Adams Middle School (or “JAMS”), happy to be leaving her job to marry a rich guy. But he's onto the fact that she's only after his money and dumps her, leaving Elizabeth with no choice but to return to the world of preteen crushes, school dances, and long, dull mornings of sleeping off hangovers at her desk while her students dutifully watch Stand and Deliver.

Then a savior arrives in the form of substitute teacher Scott (an appropriately goofy Justin Timberlake, who turns out to be a braver comedian than you may have imagined). Scott reveals that his family has money. Elizabeth immediately starts trying to seduce him but, foiled by Scott's general cluelessness, realizes she must formulate another plan of attack. She believes she needs the breasts of her dreams to pry Scott's attention from the squeaky-clean charms of Miss Squirrel, and she knows she can't afford them on a teacher's salary.

Like most good comedies, Bad Teacher is populated by familiar character actors. Some contribute greatly, such as Phyllis Smith from The Office as Elizabeth's shy (and only) friend on the staff, and Eric Stonestreet of Modern Family as Elizabeth's slovenly roommate (she found him on Craigslist). Others must grovel unbecomingly for laughs, like Molly Shannon as an over-eager parent of one of Elizabeth's lovelorn students and comic veteran John Michael Higgins as the principal who's obsessed with dolphins, a joke to which Bad Teacher returns over and over, though it never pays off.

But when Elizabeth inevitably starts caring about her students' success -- for all the wrong reasons, naturally -- and gradually grasps the sly appeal of the gym coach, Bad Teacher takes off.

Thank Segal in part, because the guy is always funny, and Timberlake gets some of the biggest laughs in a particularly crude sex scene (though the song with which his character woos Miss Squirrel is perhaps the film's funniest moment). The movie may not earn an A-plus, but at least it's far from getting an F.

BAD TEACHER

Directed by Jake Kasdan. Written by Gene Stupnitsky and Lee Eisenberg. A Mosaic Media Group release, opening Friday at Rave Franklin Park, Fallen Timbers, and Levis Commons. Rated R for sexual content, nudity, language, and some drug use. Running time: 89 minutes.

Critic's rating: * * 1/2

Elizabeth .......... Cameron Diaz

Scott .......... Justin Timberlake

Russell ......... Jason Segel