LOS ANGELES — You’ll have to say one thing for Brett Ratner’s production of Hercules: This movie has a sense of proportion. Running just over 90 minutes, the movie is often clunky, but at least it’s fast and unpretentious. And its likable star, Dwayne Johnson, manages to murder legions without ever seeming sadistic. Less violent than 300, less compelling than Gladiator, this new addition to the sword-and-sandals genre seems likely to please the fanboy audience and stir up some impressive box-office numbers.

The film begins by recounting the legend of Hercules, with snippets of his famous 12 labours. But this is not the Steve Reeves version of the tale. Johnson’s Hercules (as envisioned by comic book author Steve Moore) is a flawed hero. Bereft over the murders of his wife and children, Hercules has joined up with a band of loyal comrades who will basically sell their services to the highest bidder. In other words, they’re mercenaries. But you can bet it won’t be too long before Hercules rediscovers a noble purpose. That happens when he is enlisted by the lovely daughter of the lord of Thrace to save her kingdom from civil war. Let the mayhem begin.

The story has a few twists up its sleeve, as heroes turn out to be treacherous and villains are more complex than first appearances suggest. There’s just enough plot to keep the movie lurching forward, and there are plenty of battle scenes to delight connoisseurs of carnage. (The movie’s PG-13 rating seems fairly lenient.) One problem with these battle scenes is the frenetic editing, an unfortunate staple of contemporary action pictures. On the positive side, the sets (by production designer Jean-Vincent Puzos, who also designed one of Ratner’s favourite movies, Amour) are impressive, and the crowd scenes, even if enhanced by CGI, stir happy memories of films like Spartacus and Ben-Hur.

The classy cast also elevates the picture. Ian McShane gives a droll performance as a soothsayer who’s always surviving predictions of his own death. John Hurt is working in the glorious tradition of Claude Rains in The Adventures of Robin Hood while Joseph Fiennes is doing a Basil Rathbone as his venal confederate. As the one woman in the troupe of mercenaries, Ingrid Bolso Berdal wields a mean bow and arrow. Tobias Santelmann (star of the Norwegian Oscar nominee Kon-Tiki) has an imposing presence as Hercules’ antagonist-turned-ally.

Some of these actors have won awards, but a trip to the dais is not likely to be in the future for our star. Still, Johnson plays his role with good humour and more conviction than Steve Reeves could ever muster. When he finally breaks free of his chains and bellows, “I am Hercules,” the audience responds with just the right degree of childish glee.

There are some neat 3-D effects, but as with so many recent 3-D offerings, the format doesn’t seem absolutely essential. The cinematography by Ratner’s frequent collaborator Dante Spinotti is vibrant, and the musical score by Fernando Velazquez is rousing. Most important, the pacing is snappy. It may sound like a backhanded compliment to praise this sometimes cheesy movie for never taking itself too seriously, but in a summer of bloated spectacles, this modesty should not be underestimated.