Give credit, at least, for a clever concept: “Snow White and the Huntsman” filters a classic fairy tale through the prism of a modern, special-effects driven, action-powered blockbuster, an idea so seemingly inevitable that it’s a surprise no one has quite done it before. (Terry Gilliam’s 2005 film “The Brothers Grimm” presumably was trying for something similar, but who could tell with all that bric-a-brac on the screen?).

The result, not unlike the recent Sherlock Holmes pictures, is an intriguing mash-up of old and new. The director, Rupert Sanders (a TV commercial specialist making his feature debut), gives these familiar characters a swagger and heft — they seem more like comic-book heroes and villains than anyone you’d find in a classical fairy tale. He also borrows liberally from other modern franchises, a little bit of “Twilight” here, a whole lot of “Game of Thrones” there. If you’re looking to give your teenager a lesson in the basic tenets of postmodernism, you could probably do a lot worse.

What makes “Snow White and The Huntsman” a drag, though, is the same thing that makes so much of Hollywood’s biggest-budgeted output a drag: A barely sensical screenplay that doesn’t so much tell a story as string together noisy action sequences with geektastic backstory.

“Snow White and the Huntsman” may have started with a fresh idea, but then it got shoehorned into a style-over-substance formula — and now it’s just a chore to sit through.

In this telling, the evil Ravenna (Charlize Theron) weasels her way into the court of the benevolent king (Noah Huntley), whom she promptly marries and then murders, claiming the throne for herself.

Imprisoning the king’s beautiful daughter Snow White (Raffey Cassidy as a kid, Kristen Stewart as an adult), she keeps herself young by stealing the youth and beauty of other women — though why she bothers keeping Snow White around in the first place, even though her trusty mirror has already established the girl as a threat, is just one of the questions that screenwriters Evan Daugherty, John Lee Hancock and Hossein Amini never satisfactorily answer.

When Snow White escapes into the forest, Ravenna dispatches a roguish widower referred to as The Huntsman (Chris Hemsworth, of “Thor” fame) to chase after her — yet another plot point that the movie hasn’t worked out. You see, the evil queen also has all sorts of powers, including the ability to transmogrify herself into other people, and she even has a magical army. So why, exactly, does she need a mortal to chase after another mortal? In order to engage us, fantasy requires strict rules, but this “Snow White” just keeps making it up as it goes along.

The middle section of the movie turns into a long, repetitive chase, with The Huntsman betraying the queen and then joining up with Snow White, who is now also being tracked by the queen’s brother (Sam Spruell). She meets the requisite dwarves (there are actually eight here), and then swings her sword through a series of confusingly edited action sequences.

Every so often, the proceedings comes startlingly alive with a burst of visual imagination — a giant troll, camouflaged into the forest floor, who terrorizes Snow White, or a group of tiny, Teletubby-like sprites who emerge out of the bellies of plump black birds. In perhaps the movie’s most original use of CGI, the dwarves are all played by well-known British character actors who are much taller in real life — Ian McShane, Eddie Marsan and Bob Hoskins, among others. This at least sets it far apart from “Mirror Mirror,” this year’s other Snow White reboot, featuring Julia Roberts as the evil queen in a candy-colored, utterly bloodless wonderland.

For the most part, though, the filmmakers remain slavishly honor-bound to an overplayed rulebook. In the spirit of “The Hunger Games” and “Twilight,” “Snow White and the Huntsman” also provides a second potential suitor for its heroine — her childhood friend Will (Sam Claflin, “The Pillars of the Earth”), now a hunky grown-up leading the rebel forces against the queen’s tyrannical rule. In terms of personality, the two men are indistinguishable — the only way to tell them apart is that Hemsworth sports facial hair, and the other guy looks as if he’d rather be singing in a boy band.

As for the lead actresses, it would be nice to report that Stewart and Theron lend the summer movie season something it hasn’t had in years — a blast of girl power. Yet much like in the “Twilight” movies, Stewart comes off as petulant and visibly uncomfortable with her own movie stardom. Luckily Theron has a much grander time, screaming and writhing on the floor and employing her best Joan Crawford-in-“Mommie Dearest” death stare. But the actress drops out of the proceedings for long, long stretches, and the movie flatlines in her absence.

Talk about a depressing irony: Even when women are at the center of the story, modern Hollywood blockbuster-making still manages to give them nothing to do.