Jessica Rothe in Happy Death Day.

A college girl learns a few lessons about life—and about not being a total ass—by re-living the day she is murdered over and over again in Happy Death Day, a so-so movie that gets by completely on the power of its relative unknown lead actress, Jessica Rothe.

Rothe plays Tree Gelbman, who wakes up in a strange dorm room on the morning of her birthday to discover she has spent the night with a bit of a dweeb, Carter Davis (Israel Broussard). She storms out of the room while ignoring phone calls from her dad—and basically being nasty to everybody she comes across during her walk of shame. It’s established quickly that Tree is a jerk—and that she has more than a few enemies.

All of those enemies, and even some of her friends, become murder suspects when Tree is killed by a mask-wearing baddie on her way to a party that evening. After her life force is snuffed out, she immediately wakes up in Carter’s bed again. She goes about the same day thinking it’s just déjà vu, but when she is murdered again, and wakes up in the same bed on the same day again, she figures things out. She’s living a murder mystery, Groundhog Day-style.

The list of suspects is long. There’s Lori (Ruby Modine), the caring, neglected roomie who baked her a cupcake for her birthday. Then there’s Gregory (Charles Aitken), the slimy teacher she’s having an affair with, and there’s Tim (Caleb Spillyards), the creepy stalker-type who took their one date a little too seriously. Carter can’t be scratched off the suspect list, nor can Tree’s dad (Jason Bayle). Director Christopher Landon and writer Scott Lobdell pile on so many suspects, then break so many rules, that it becomes virtually impossible to guess the killer. I guess that’s a good thing.

Rothe comes out of nowhere to make this movie more than a rip-off of the classic Bill Murray vehicle. She was one of Emma Stone’s friends in La La Land; that’s where most people have seen her before. She sort of has a Rachel McAdams-meets-Piper Perabo thing going.

This is the darkest of dark-horror comedies, and it takes major acting chops to keep something this repetitive both engaging and humorous. Rothe is playing a jerk you are supposed to start to like and even root for as she learns a few lessons and becomes a better person. Even though her character is a pompous twit at the start of the movie, Rothe manages to make her a funny, semi-likable pompous twit, so that the audience can hang in there and get invested in her character’s evolution.

While the movie isn’t horribly scary, it’s scary enough to put it alongside another horror spoof, Scream. Actually, you could make the argument that Happy Death Day rips off both Groundhog Day and Scream shamelessly. The movie even mentions Groundhog Day at one point, making it clear the filmmakers are aware of what is getting copied.

When the movie wrapped after what turned out to be a pretty good fake-out ending, I realized I’d had a relatively good time watching it. (I also appreciated the little nod to Sixteen Candles.) It’s PG-13, so if you like your horror movies hardcore and super-bloody, you may feel let down.

Happy Death Day is a decent-enough movie, and it marks the arrival of an actress you’ll probably be hearing a lot about in the near future. If she can make something as contrived as this enjoyable, imagine what Rothe could do with some real material.

Happy Death Day is playing at theaters across the valley.