BAD TEACHER OPENS with its titular protagonist Elizabeth (Cameron Diaz) on the last day of the school year. In a tight dress and Louboutin heels, she's kissing her job at the middle school goodbye, her apparently lifelong gold digging having successfully yielded a meal ticket. Flashbacks over the past year (her only one at the job, at least at this school, but who knows—we never learn anything of her past) introduce us to her character as a binge-drinking, pot-smoking, conniving slacker who sleeps off daily hangovers at her desk while her students watch movies. Unfortunately, from here out, Elizabeth's behavior only gets a little bit worse but a lot more predictable.
Dumped by her would-be sugar daddy, Elizabeth returns to the classroom and tries to sink her claws into Scott Delacorte (Justin Timberlake), the odd, boyish new substitute who she quickly deduces is an heir, thus setting up a rivalry with her creepily chipper coworker Amy (Lucy Punch). Meanwhile, gym teacher Russell (Jason Segel, who plays the film's coolest character with one hand behind his back) is making moves on her despite her standard response: "Are you still a gym teacher? Then fuck you."
Elizabeth's one guiding motive is to raise $10,000 for breast implants, which leads her to embezzling the profits of the seventh-grade carwash and sending a heavy to threaten the head of a standardized testing firm, among other things. Most of her antics involve using sex appeal as a weapon, but these scenarios are so standardized that to be offended would wildly outdo the energy put forth to write them.
Unlike other films the title seems to intentionally evoke (Bad Santa, both Bad Lieutenants), Elizabeth's behavior is self-serving, but not spectacularly self-destructive. Despite the liquor bottles in her desk and late-night munchies involving corn dogs dipped into jars of mustard, she always manages to curl her hair, apply copious eyeliner, reap the power of a smokin' body, and in short, win. Sure, she denigrates humanity at large, saving particular scorn for her peers and obliviously dropping terms like "blacks," "the Jews," and "Orientals"—and all of that is "bad," but like much of the film's forced writing, it exists only to make a cheap grab at edginess.
Teacher's humor, while amusing, rarely executes anything more clever than simplistic immaturity, wherein any teacher who says "fuck" is inherently hilarious, and sexy ladies can effortlessly trick men while taking on fatties as abused sidekicks, because that's just how the world of cinema works. Throughout is the sense that a more clever—or at least a grimier—version of this film exists somewhere on a cutting-room floor, but Bad Teacher doesn't do much to inspire a search. Better to just let this version roll while you doze through a hangover with a bong and some corndogs close by.