If the title of Jake Kasdan's Bad Teacher calls to mind Bad Santa, the resonance is deliberate: Here is a comedy full of inappropriate humor about someone filling a familiar role who couldn't be further from the figure of benevolent authority we expect.
In this case, it's Cameron Diaz as Elizabeth Halsey, a middle-school teacher who doesn't bother to learn her kids names and spends class time showing them movies about teachers (Stand and Deliver, Lean on Me) and guzzling from airline-size bottles of liquor she keeps hidden in a false bottom of a desk drawer.
The result is a movie which, while never producing the kind of uproarious guffaws of Terry Zwigoff's Bad Santa (we were so innocent back in 2003), still offers a regular diet of laughs. There are lags and problematic pacing. But Diaz has the sass and confidence to make the character funny, even when the material is inconsistent.
Kasdan, who directed Walk Hard: The Dewey Cox Story and The TV Set, establishes Elizabeth early as someone who is always inappropriate and never caught short. She's first seen accepting a going-away gift at the end of her first (and apparently only) year of teaching because she's leaving to get married. The farewell party, however, is a tad premature: Her rich boob of a fiancé has finally gotten wise to her gold-digging intentions and dumps her before the wedding.
So she's back teaching English at the same suburban Chicago middle school the following fall, with two goals in mind: She's going to earn enough money to pay for a boob job - and then use her newly enhanced chest to land a rich husband. She even has one in her sights: a clean-cut substitute teacher (Justin Timberlake), who comes from money and is just getting over a breakup of his own.
Teaching is the last thing on Elizabeth's mind. She's looking for schemes to drum up the cash she needs ($10K!) for her breast enlargement. She's also doing her best to shirk things like lunchroom duty and actual teaching, which irks the aptly named Amy Squirrel (Lucy Punch), who has the classroom across the hall. Amy, who regularly wins awards for her industriousness and hard work, suddenly finds herself playing second fiddle to a teacher who obviously isn't, hasn't and won't pay her dues.
There is, of course, a throughline, involving Elizabeth's melting reluctance to engage with her students -- though there are no sudden changes of heart or approach. When she suddenly buckles down to actually teach, it's because there's a bonus for the teacher whose students score the highest on the state's standardized tests. She becomes a good teacher in spite of herself.
Punch makes a great comic foil for Diaz's flinty-eyed scheming, as does John Michael Higgins, who plays a principal with a dolphin fixation who is easily manipulated by the slinky Elizabeth. Jason Segel is also consistently funny as a gym teacher who is nearly as jaded as Elizabeth and is set on getting her into bed. For good measure, watch for Phyllis Smith (from "The Office"), who steals all of her scenes as a waffling colleague who is drawn to Elizabeth's bad-girl aura.
Bad Teacher isn't a great comedy by any stretch. But it provokes more regular laughs than The Hangover Part 2. There are worse ways to spend your time.