“The Little Hours”

***

(R, 1:30)

Get thee to the nunnery of “The Little Hours,” a smutty comedy starring Alison Brie, Aubrey Plaza and Kate Micucci as 14th-century nuns in heat. This Sundance grad from writer-director Jeff Baena is bawdy, blasphemous and very funny when on its game, which isn’t always.

Based on a few pages from Giovanni Boccaccio’s “The Decameron,” “The Little Hours” is set in a Tuscan convent overseen by Father Tommasso (John C. Reilly) and Sister Marea (Molly Shannon), each more interested in the other than what their nuns are doing. Three are already breaking their vows regarding profanity.

Alessandra (Brie), Fernanda (Plaza) and Ginerva (Micucci) swear like Philistines, part of the modern spin Baena gives Boccaccio’s words. Despite its medieval setting, “The Little Hours” takes a sorority-house approach to these nuns’ personalities and casual syntax, dishing on other nuns and lusting for the new deaf-mute servant Massetto (Dave Franco).

Actually, Massetto can hear and speak, but Tommasso thought better of it when hiring the fugitive. Massetto was hooking up with a nearby queen when the king (national treasure Nick Offerman) found out. Playing deaf and mute should keep Massetto out of trouble with the nuns. Of course it won’t.

A virile poser tempting chaste women in a raunchy period piece sounds like an SNL take on “The Beguiled” or a Woody Allen sketch from the ’70s. Baena has other mortal sins in mind besides sex, no less heresy than witchcraft, all played for laughs and/or dropped jaws. “The Little Hours” will gladly offend anyone.

Brie is fine as the “stable” side of the nun triangle, and Plaza’s wild-eyed line deliveries are amusing or annoying, take your pick. The trio’s standout is Micucci, half of the Garfunkel and Oates comedy music duo, whose Ginerva is a mouse who eventually roars, clumsily following in her sisters’ profane footsteps. Franco’s befuddled grins and cringes come in handy dealing with them.

“The Little Hours” is peppered with comical moments: Reilly hearing Franco’s confession, Paul Reiser as Alessandra’s father who can’t raise her dowry/convent bailout, Fred Armisen as a visiting bishop uncovering the convent’s sins, anything Offerman says in stone-faced jest. “The Little Hours” is less than the sum of its many comedy parts, but some of those many are hilarious.