Maybe the time has come to give the Cinderella story a rest for a while.

“A Cinderella Story” is the third retelling this year of the beautiful-girl-finds-her-Prince Charming myth (after “The Prince & Me” and “Ella Enchanted”), and the results have been on a steady decline, culminating (for now) in this listless, charmless, humorless and resolutely nonenchanting movie that should appeal only to teen and preteen girls who desperately want to be star Hilary Duff (or who have desperate crushes on co-star Chad Michael Murphy).

They, one supposes, will get their money’s worth; Duff is in almost every scene, and Murphy is ceaselessly adorable. (Though, to be fair, he does bring an appealing vulnerability and approachability to the role). But the story is without an original thought, the characters little more than caricatures (unappealing ones, at that) and the filmmaking so uninspired that it’s hard to imagine anyone embracing it with anything more than a shrug and a wonder why they didn’t wait to catch it on TV.

Duff, laying on the ceaseless spunk and teary-eyed wistfulness a little heavy, is Sam Montgomery, a confirmed daddy’s girl until her father dies while aiding her wicked stepmom during an earthquake. Years pass, and she’s now a high school senior with her sights set on Princeton, much to the dismay of her vacuous, Botoxed stepmom (Jennifer Coolidge), who wants all the glory for her two natural daughters and is determined that Sam spend the rest of her years swabbing the floors of the family diner.

Sam, of course, has other plans. She’s also got a secret beau, a mysterious stranger she met in an Internet chat room who also has plans to attend Princeton, and also is rebelling against his parent’s (in this case, his dad’s) plans. The audience quickly discovers her unknown soul mate is star quarterback Austin Ames (Murphy), a gorgeous hunk with the soul of a poet (and, of course, the requisite mean, spiteful cheerleader for a girlfriend).

The two mystery lovers eventually meet at a costume ball, where she recognizes him, but he doesn’t recognize her; she’s wearing a tiny mask over her eyes, which makes her look remarkably like Hilary Duff with a tiny mask over her eyes, but it’s apparently enough to fool Austin. Unable to tell him the truth, Sam flees the dance, leaving her cell phone behind.

Will true love win out? Will all the meanies get their comeuppance? Will filmmakers ever tire of recycling the same stories in the same way with the same disregard for their audiences, who at least deserve a little creativity and spontaneity for their moviegoing dollar? No prizes for guessing the right answers, save for the realization a better movie might be in order for tonight.