Based on Rosalind Wiseman's nonfiction best-seller Queen Bees and Wannabes: Helping Your Daughter Survive Cliques, Gossip, Boyfriends, and Other Realities of Adolescence, Mean Girls is a success in that it delves into one of the lesser exploited aspects of teen comedy -- the innermost dynamics of backstabbing among adolescent girls. Complemented by a slew of SNL regulars and alumni -- particularly Amy Poehler's turn as a desperately eager-to-please, aging, and augmented trophy wife of a mother -- the film is best when at its bitchiest. To its credit, protagonist Cady (Lindsay Lohan), whose only previous educational experience was provided by her zoologist parents in the wilds of Africa, is not the pure-hearted heroine of teen flicks past. Her agenda of sabotaging the Plastics (the school's most simultaneously feared and envied clique, led with aplomb by "professional life-ruiner" Regina George [Rachel McAdams]) from the inside may have begun with noble intentions, but when her efforts land her the head position in the "army of skanks" she had sought to dismantle, she is hardly reluctant to assume the role, at least initially. However, for pegging the darker subtleties of high school so well -- the lunchroom caste system, the mechanics of manipulation, the evolution of a rumor, transitions of power, and the ever-present threat of weight gain, to name a few -- Mean Girls loses a certain amount of punch in its ham-fisted later half, which involves an excruciatingly out-of-place trust fall and a clichéd speech (at the Spring Fling, no less) in front of the entire student body. Yet, despite several cheesy epiphanies, Mean Girls is a self-aware, solid effort at dissecting the superficialities of high-school life, particularly for post-Columbine times. Besides, there's always Heathers.