A pregnant Sam (Allison Miller) has a hard time understanding the dark changes to her body in “Devil's Due.” (Michele Short)

A “Rosemary’s Baby” for the “Paranormal Activity” generation, “Devil’s Due” uses the increasingly unimaginative found-footage gimmick to try to juice up the tired trope of a woman who is carrying a demonic fetus.

That’s not a spoiler. The movie’s two-word title is the world’s shortest plot synopsis, and the trailer gives away even more. What few surprises lie in store arrive very late in the film, and consist of generic supernatural horror clichés (sub-genre: the occult). In other words, expect arcane religious symbols, Latin incantations and levitation.

To the film’s credit, the appealing young performers Zach Gilford and Allison Miller are well cast as newlyweds Zach and Sam, who find themselves expecting a child after a drunken night on the town in a creepy subterranean nightclub while on their honeymoon. Most of the film is presented as Zach’s home movies, though directors Matt Bettinelli-Olpin and Tyler Gillett (who worked together on “V/H/S”) supplement that with footage from other cameras.

Conveniently for the filmmakers, Zach and Sam’s house gets broken into shortly after they learn she’s pregnant, and several “Paranormal Activity”-style surveillance cameras are hidden by the intruders, unbeknownst to Zach and Sam. This results in a movie that, as with most other examples of the genre, looks like it was shot by a 13-year-old with a $2,000 gift card from Best Buy.

There’s virtually no suspense here. For the first two-thirds of the movie, weird — yet entirely predictable — things start happening to Sam. First, there’s a nosebleed, then unexplained bruising, followed by uncharacteristic outbursts of rage and sudden cravings for raw meat (whether in the form of steak tartare in the grocery store meat section or an impromptu snack of freshly harvested venison from the local park). “Something’s wrong!” wails Sam. Ya think?

It’s more silly than scary.

The film’s real frights take their sweet time coming, yet once they do, in the film’s final act, they’re nothing that any horror fan hasn’t seen a number of times before.

This would be just fine and dandy for those of us who don’t mind going through the horror-movie motions. There’s a certain — albeit minimal — pleasure to be had in experiencing the exact same starts that have startled us before.

What’s most irksome about “Devil’s Due” is the sloppy logic of the found-footage concept here. The movie opens in a police interrogation room, where a bloodied and handcuffed Zach — denying that he “did it,” whatever it is — is being grilled. What follows is supposed a documentary record of “it,” except that, by the end of the film, much of the footage that we’ve just watched is shown to have been lost. In one scene, an entire cache of Zach’s digital-video storage disks — ones we’ve just seen, by the way — is stolen from his home office.

So how exactly did they wind up in this movie? And wouldn’t it be simpler if Zach, instead of protesting his innocence, just bought the cops a ticket to “Devil’s Due”? On the other hand, I can understand their reluctance to sit through it.

R. At area theaters. Contains obscenity, violence and gore. 89 minutes.