The majority of feature films are based on popular young-adult novels full of angst, comic books brought to life through a massive amount of special effects or top-selling novels that come with a built-in audience.

“The Little Hours” will have to find an audience in a different way. It’s based on a collection of novellas titled “The Decameron” written by Giovanni Boccaccio long before there were bestseller lists. Boccaccio’s work was composed in the 14th century.

The book features 100 tales covering a wide range of topics. For this adaptation, writer/director Jeff Baena (“I Heart Huckabees”) has taken a bit of the original collection and turned it into an offbeat blend of a 14th-century cautionary tale with a satirical modern touch.

The tale unfolds during the latter part of the Middle Ages in a convent where most of the nuns are unstable. Alessandra (Alison Brie) has been sent to the convent while her father (Paul Reiser) tries to pull together a dowry that will most likely never happen. She’s friends with Genevra (Kate Micucci), a virgin hiding a dark secret about her religious history.

They tend to follow Fernanda (Aubrey Plaza), a nun completely lacking in grace, love for her fellow person, commitment or religious passion. This attitude is mixed with a mysterious need to head into the woods late at night with the convent’s donkey.

These three are so abusive (using language that’s salty for the 21st century) to the convent handyman that he quits. When Father Tommasso (John C. Reilly) runs into Massetto (Dave Franco), a young man in need of a place to hide, he comes up with a plan to have him take over as the handyman. Massetto agrees to pretend to be deaf and unable to speak so he can avoid conversations with the nuns.

Talking is about the only thing Massetto doesn’t do with them.

Baena bounces the players through a bizarre series of events that deal with love, lust, witchcraft, religion and elements that don’t often appear in a tale set in a convent. The way Baena has written and directed the movie, it plays more like a modern tale of sexual antics.

It works because Brie, Micucci and Plaza attack the roles with unbridled energy. Micucci has made a career out of playing quirky characters but they all pale to the absurdities of her Genevra. Plaza always looks like she’s having a wicked good time when she gets to play a character who lives to defy the rules.

This isn’t the first time Boccaccio’s writing has been turned into a big-screen production. It was first approached on film in 1971 by Italian director Pier Paolo Pasolini. That production featured 10 vignettes, with the tale of the young man and the lustful nuns as the plot of just one of them. Because it was only a small part of the overall movie, its inclusion didn’t raise many complaints.

That’s not the case with this film, which has drawn the ire of the Catholic League as an assault on conventional religious thinking. Its message is that girls just want to have fun, even in a convent in the Middle Ages.