Rating: Three Stars

If not for its PG-13 rating, “Jack the Giant Slayer” would be an old-fashioned, family-oriented fantasy adventure, the type that local television stations used to run on Sunday afternoons.

Just a few edits would have guaranteed a PG, but that rating is considered uncool these days. Parents wondering if this is appropriate viewing for their children should take the PG-13 under advisement. The main reason for the rating is a particularly grotesque, almost comical, death of a giant near the end of the film, and like almost all of the film’s violence, it is rendered in CGI.

The rating aside, Bryan Singer confidently captures the earnest spirit of such mildly scary family features as “Jason and the Argonauts” and “The Seventh Voyage of Sinbad.” Those classics had Ray Harryhausen’s stop-motion creatures and “Jack” has CGI giants. The giants aren’t especially realistic, but neither were the skeletons in “Jason,” and 50-plus years on, that fight at the end remains a thrilling special effects sequence.

Nicholas Hoult, recently seen as an undead Romeo in “Warm Bodies,” plays the title role in the adventure, which is much more a retelling of “Jack and the Beanstalk” than “Jack the Giant Slayer.” The confusion is understandable. Both are old English folk tales involving a hero named Jack and giants, and Mickey Mouse did star in versions of both. But “Jack and the Beanstalk” sounds like a kids movie, and “Jack the Giant Slayer” sounds like an action movie, so now you know why the producers picked which title.

The script, credited to Darren Lemke, Dan Studney and Singer’s “Usual Suspects” collaborator Christopher McQuarrie, takes the beanstalk legend and layers in some palace intrigue and a Disney-like subplot about a runaway princess (Eleanor Tomlinson) who falls in love with peasant boy Jack.

The princess, Eleanor, has been betrothed to a much older suitor, Roderick. We know he is a conniving weasel because he is played by Stanley Tucci with an arch English accent. The kind-hearted king (Ian McShane) wishes his daughter would behave, but she keeps disguising herself as a commoner and running off.

A storm arises during one of her escapades, so the princess seeks refuge in the shanty home of Jack, who recently acquired some “special” beans in a transaction familiar from the fairy tale. Jack’s infuriated uncle already has thrown away the beans, and one has settled beneath the house. When rain water activates the legume, a towering stalk carries the cabin into the sky, taking the princess with it.

In this telling of the tale, a war between men and giants occurred generations earlier, so everyone in the kingdom already knows about magic beanstalks and the land of giants above the clouds (which makes it curious that Jack doesn’t suspect the offer of “special” beans). The king dispatches his finest soldiers to climb the beanstalk and save his daughter from the hungry giants. Jack and the scheming Roderick, who knows a few secrets about the giants, tag along because otherwise there wouldn’t be a movie.

From this point on, “Jack” plays out like the original “Star Wars” in ren faire costume. To save a princess, a farm boy goes on a perilous mission led by a venerable knight played by genuine Obi Wan Kenobi Ewan McGregor, who actually says, “I’m getting an awfully bad feeling about this.” The “awfully” must have been thrown in to prevent George Lucas from suing for plagiarism.

“Jack” may not be original, but it is fun. These days, too many makers of big-budget action movies seem so embarrassed by their material, they try to prove there are above it – and the audience – with a snarky attitude. “Jack” is not without a sense of humor, but Singer takes the story at face value, magic beans and all, and the cast plays it straight. I enjoyed how McGregor casually says, “Tally ho,” before leaping into action.

Holt and Tomlinson are charming as the young heroes, and Tomlinson looks dynamite when she dons Joan of Arc armor toward the end. The giants are fearsome villains, with Bill Nighy playing their two-headed leader (a two-headed giant is one of the few elements from the “Giant Slayer” legend).

For all that, “Jack the Giant Slayer” is Singer’s best film since the second “X-Men” movie. It is charming, exciting and unashamed of its corny virtues. Someday, it will go down easy on a lazy Sunday afternoon.