‘Rampage’ review: Dwayne Johnson’s latest is enjoyably ridiculous

If you’re willing to buy Dwayne Johnson as a primatologist with a Special Forces background, then everything else in the enjoyably ridiculous monster-movie “Rampage” should be an easy sell. A tale of three normal-sized animals genetically transformed into city-wrecking behemoths, “Rampage” mixes high levels of testosterone with something that can only be called preposterone, and the combination makes for absurdly good entertainment.

We’re hooked from the start, when a terrified doctor scrambles through a blood-spattered space station to escape from a severely disturbed lab rat. We don’t need much more than an uncaring female voice on the intercom (and 40 years of “Alien” movies) to deduce that a sinister corporation is behind all this. Three of the doctor’s canisters go tumbling to Earth and, as luck would have it, land in spots teeming with wildlife.

Among them is a San Diego preserve where staffer Davis Okoye (the always likable Johnson) has developed a deep bond with an albino silverback gorilla, George (a motion-captured Jason Liles). They laugh, joke and make crude wisecracks, all in sign, but one morning Davis discovers that George is growing at a frightening pace and developing a violent temper. It turns out George inhaled a mysterious gas from one of those canisters — as did a wolf in Wyoming and a crocodile in the Everglades.

One reason we buy all this nonsense is a deft script (by Ryan Engle and others) that doesn’t try too hard to turn what was originally a Bally Midway video game into plausible science fiction. When geneticist Kate Caldwell (Naomie Harris) joins forces with Davis and says something about gene-editing — “the growth rate of a blue whale, the strength of a beetle!” — we’re basically satisfied. Likewise, the film’s villains, a brother-sister bio-tech team (Jake Lacy and Malin Akerman) are about as realistic as Saturday morning cartoon characters and every bit as fun. They’re the ones who lure the animals to Chicago with a special radio frequency that sounds like this: “beee-yooop!”

It’s all a hoot, energetically directed by Brad Peyton (now on his third film with Johnson) and filled with inventive special effects that turn downtown Chicago into a jungle gym for the towering creatures. Jeffrey Dean Morgan, as a vaguely defined government agent named Russell, sums up the film’s less-than-serious tone when he casually tells our heroes, “Thank you for saving the world.”