Pay attention, my friends, this one is a little bit tricky. In his last movie, Dwayne “The Rock” Johnson played an avatar in a movie about a video game. In Rampage, he plays a human in a movie based on a video game, though in the video game, big in arcades in the 1980’s, it was the animals who were the avatars, and your task as player was to help them destroy the city while Johnson’s human character in the film is there to protect it.

Still with me?

Well, maybe “human” does not adequately describe Johnson’s character, the primatologist/Special Forces veteran Davis Okoye, the essence of movie hero, always ready with his fists or a quip or both at the same time. And, you know, he looks like The Rock.

Okoye works at a San Diego animal preserve, where he is especially close to an albino gorilla named George. They communicate via sign language. And it’s all downright Edenic until George is hit with spray from one of three canisters of gene-altering material that “edit” his DNA to make him grow to King Kong size and make him furious, aggressive, and destructive.

With the help of the beautiful scientist who developed the gene-editing juice, hoping to help humanity and not in any way aware that the evil corporation she was working for was planning to weaponize it. Naomie Harris plays Dr. Kate Caldwell, and Jake Lacy and Malin Akerman are the oh-so-evil brother and sister who run the corporation. Well, she’s evil; he’s way over his head. Then there’s Joe Manganiello as a mercenary hired by the evil sister, Jeffrey Dean Morgan as a FBI official with a Southern accent, and a walloping lot of CGI as the three monsters — those two other canisters — Okoye has to find a way to stop.

If they ever give out an Oscar for efficiency of set-up, this movie is a contender. It quickly assigns an attribute to each character and lets us know immediately what the stakes are in every scene. Director Brad Peyton (“San Andreas,” also starring Johnson) knows we’re here for the action, and spends just enough time between scenes of shootouts, explosions, and chases to remind us why we should care what happens to the characters. Manganiello’s character has a big scar on his face, so we know he’s tough. The evil sister says, “There’s a reason we were doing these experiments in space and it wasn’t for the betterment of humanity,” just to make it clear that she is the bad guy. In case we missed it the first time, when her hapless brother says, “You can’t liquidate all your problems,” she snaps back, “Agree to disagree.”

And Dr. Kate lies to her boss on the phone, so we know that she is not a rule follower. Plus, we glimpse a photo in her apartment showing her hugging a cancer patient, so we know she is nice and probably bereaved. Morgan’s FBI character has a seen-it-all, heard-it-all look but a bit of a twinkle in his eye. And a homing device has the three giant, hungry, and very hostile animals going full-speed to Chicago.

Does any of it make sense? Not really. Do we care? Not really. Just don’t think too hard about how long it would take for debris to fall from space, what condition it might be in, or how long it would take an antidote to work. This is a movie based on an arcade game, and it is much better than most game-based films.

In part that is because the game was from the 80’s and didn’t really have a storyline, so there was no risk of being too faithful or not faithful enough, and in part because it never takes itself too seriously. It takes the stunts and action seriously, though. There’s a wow of a plane crash and some good moments in the midst of a massive destruction of Chicago’s Loop. And George (motion capture actor Jason Liles) is, if not realistic, believable. Johnson is right in his sweet spot here, and so are we, with a popcorn treat to kick off the summer season.

Parents should know that this film includes extended peril and action-style violence with chases, explosions, guns, bombs, monsters, many human and animal characters injured and killed, some graphic and disturbing images, some strong language, and some crude humor.

Family discussion: Who should make the rules about genetic experimentation? Who in this film follows orders and who does not? Why did Davis say he was not a “people person?”

If you like this, try: “Jumanji: Welcome to the Jungle” and “Transformers”