“How to Be Single” is an unromantic romantic comedy, which makes it something different. Yet it feels just like any other romantic comedy only with the romance missing, so it’s not exactly something new. The movie is an attempt to adapt an old form to new times, and the result is interesting, but a little off; honest for long stretches and then phony in the most obvious way.

Still, for at least an hour, “How to Be Single” is a pleasurable experience, with its brutal and coarse humor and the sense it gives, false or not, of a dispatch from the front lines of modern courtship. Things doesn’t look easy out there. Modern love looks really confusing, with lots of rules within rules that all seem to conspire to keep people unattached.

At the center of the movie — another plus — is Dakota Johnson, best known as the star of “Fifty Shades of Grey” and the only thing that makes the prospect of a sequel to that film even bearable. Johnson has a magnetism on screen that’s hard to define, a look that seems to change from scene to scene, virtually from shot to shot. Her line readings are odd but true, and her emotions are close to the surface. It’s downright amazing how well she is sometimes able to enliven pedestrian writing here, the way she did in “Fifty Shades.” Watching her in a break-up scene, you can almost feel physically, just by watching her, what her character is going through.

She plays Alice — a name that, for some reason, you hear more often in movies than in life. At the start of the film, she has decided that she and her boyfriend need to take a break from exclusivity; otherwise, she will never know what it’s like to be on her own. To make this temporary break more real, she relocates to New York City and moves in with her older sister (Leslie Mann), an obstetrician. She also makes friends with a co-worker (Rebel Wilson), a blackout drunk who has a new partner every night.

“How to Be Single” operates on a wide canvas, covering the yearnings and behaviors of a number of characters, even ones not in Alice’s immediate circle. There’s Alison Brie as Lucy, a fussy — and funny — control freak, who has developed an algorithm for finding a love match online; and Tom (Anders Holm), a bartender, committed only to staying uncommitted and having a succession of lovers.