“Will I be able to understand it if I never saw the first two ‘Step Up’ movies?” asked a friend. Uh, you’ll be able to understand it if you have never seen a single movie and don’t speak English. All of the energy, imagination, and attention in this movie is on the dance numbers, which is where it should be, and it pays off just as we hope.

Here is the plot: Kids dance. There is a romantic misunderstanding. There is a big competition with a hundred thousand dollar prize. And kids dance some more. In 3D.

The dances are sensational, making brilliant use of the 3D technology, not just to have things coming toward us but to create a sense of depth that has the audience feeling like a part of the action. There are some great effects with lights, as well. The movie also makes great use of New York City locations, including Central Park (with balloons and soap bubbles), Times Square, and the NYU campus. I like the way they mix it up with the dancing. It’s not just the rubber-limbed acrobatics and thumping of hip-hop, crunk, and what we used to call break-dancing back in the day. There’s a marvelous masked tango to Jazmine Sullivan’s “Bust Your Windows” and an adorable nod to screen legends as Adam G. Sevani (Moose) and Alyson Stoner (Camille) dance along a sidewalk to Fred Astaire’s “I Won’t Dance,” with Gene Kelly’s garbage can lid step from “It’s Always Fair Weather.”

This is the kind of movie where the dialog is pretty much “This is our night!” “Dance can change everything!” “Follow your dream.” But it’s also the kind of movie where our hero is followed into the bathroom by a mean-looking rival out for revenge — and it turns out that the other guy just wants to out-dance him. There’s a Benetton ad of dancers, each with slick moves and attitude to spare and names like Cable and Wave and Radius. We see a lot of game faces in competition, but when they’re home it’s all about “this is my real family.” I got a kick out of an updated twin version of the Festrunk Brothers (Facundo and Martin Lombard). Everyone lives together in a cool and blissful boho loft, complete with graffiti room, practice space, and boom box wall, with no jealousy, selfishness, impatience, or arguments about chores. And everyone loves to dance.

What little plot there is centers on Moose (returning from “Step Up 2 the Streets”) and his BFF Camille as NYU freshmen and Luke (Rick Malambri), a sort of ring-leader/father figure trying to keep his group together but behind on the rent and falling for new girl Natalie (Sharni Vinson of “Home and Away”). The World Jam is coming up. Can Moose finish his exam in time to be there for the preliminary? Will the rival team led by a rich snob cheat? Will some new moves save the day? Will there be a “Step Up 4ever?” Bring it on!