Starring Jena Malone, Mandy Moore, and Macaulay Culkin. Rated 14A.

There's nothing more conventional than the high-school comedy--except maybe for a high-school comedy set in a Christian high school, in which the rules can pretty much wipe out everything else. We're not talking Catholic here, with nuns and rulers and all that sublimated sexuality, but that newfangled Clairol Christianity, with squeaky-clean smiles, blond hair that crosses all ethnic boundaries, and rap music for Jesus.

In Saved!, which pokes knowing but not entirely irreverent fun at these protest-free Protestants, the conventions are both subverted and observed, thanks to an edgy script and an even sharper cast. Up-and-comer Jena Malone stars as a true believer whose faith is shaken when her long-time boyfriend (Chad Faust) confesses that he "might" be gay. She's shocked--he was such a great ice skater, after all--but determines that it will be worth the ultimate sacrifice to "degayify" him. Naturally enough, she gets pregnant after just one try, and even more naturally, her name is Mary.

This change of provenance threatens Mary's standing with the Christian Jewels, a pop group and a trio led by Hilary Faye (Mandy Moore, in manic-bitch mode), who lords her popularity over the other, less fortunate kids at American Eagle High. The resident troublemaker at this Columbine-in-the-making is Cassandra (cast standout Eva Amurri), a ciggy-smoking, potty-mouthed Jewish girl who has been sent to the school as a kind of last chance for redemption. Instead, she corrupts Faye's wheelchair-bound brother (Macaulay Culkin, with his phasers set on smirk) and is the first to spot Mary's delicate condition--and to offer some human, if snarky, comfort.

There's not much help coming from Mary's mother (Mary-Louise Parker), absorbed in her duties as "the number-one Christian interior decorator in the region", according to a recent award. And Mom is even more distracted by her "consultations" with Pastor Skip (Hal Hartley veteran Martin Donovan), a hip-talking new schoolmaster caught between feelings and beliefs. Fortunately, single dad Skip has an even cooler son (Almost Famous lead Patrick Fugit) who takes an immediate shine to our burgeoning heroine. On the other hand, Faye likes him, too.

Keen observers of teen fare will recognize more than a passing similarity to other such comedies, most notably the recent Mean Girls, which was also about queen bees brought down by outsiders. Saved! could have used some of the thoroughness that screenwriter Tina Fey put into the earlier film, especially in explaining what made these girls so mean. (Faye's mother is only glimpsed here, but the answers are obviously found in that frightening quarter.) Here, instead of going deep, director Brian Dannelly, working from the script he wrote with Michael Urban, goes wide, cramming as much activity as he can fit into the B.C.-shot film's closing section. The decoration proves to be a bit baroque, shall we say, for such puritan architecture. But there's much to admire, and laugh at, in Dannelly's impulse to resolve the contradictions that, in the end, make these characters more human than divine.