Entertainment

‘Prince of Persia’ is a sand trap

Thanks to a magic dagger that allows its user to go back in time and change history, “Prince of Persia: The Sands of Time” may be the first movie that effectively erases virtually its entire story line by the very last scene.

Disney and its resident mega-producer Jerry Bruckheimer (“Pirates of the Caribbean”) needn’t have bothered. I’d wager not many people are going to remember much of this corny, highly derivative would-be franchise inspired by a video game, even if it carries a reported $200 million price tag.

Although “Prince of Persia” seems aimed at 10-year-olds, it will be tolerable for older folks because of its more amusing aspects. Chief among them is surely the casting of erstwhile emo boy Jake Gyllenhaal — arms pumped out to there and sporting a posh Oxbridge accent — in the title role. To paraphrase “Brokeback Mountain,” perhaps that movie’s star thought this turn in a blockbuster would “complete” him.

Jake’s Prince Dastan is a former street urchin adopted by the wise old king and raised alongside the king’s two other sons.

Climbing up on arrows that miraculously pierce stone walls, Dastan leads the charge on a religious city. Dastan and his brothers have been misled to believe it’s hiding the ancient equivalent of weapons of mass destruction (some things apparently never change in the Middle East).

Dastan does discover the aforementioned dagger — complete with a jewel in the hilt that functions like a video-game controller — along the beautiful and feisty Princess Tamina (recent James Bond girl Gemma Arterton, as hilariously inauthentic as Gyllenhaal).

It’s hate at first site on her part, but that doesn’t stop Tamina from spiriting Dastan out of the city when he’s blamed by his brothers for a wardrobe malfunction — straight out of a ‘50s B-movie — that kills their father.

Even for a summer blockbuster, this committee-written effort is notoriously weak in the logic department. It’s not really giving away much to report that Dastan’s eyeliner-lovin’ uncle Nizam (Ben Kingsley) has his own nonsensical plans for the magic dagger.

Tamina, meanwhile, has for some reason been waiting around for Dastan’s arrival to “fulfill my destiny” — (I believe she also uses the term “it is written”) — and prevent the dagger from being used to inadvertently destroy mankind.

Yes, it’s another one of those summer movies. In this case, Tamina’s “destiny” essentially leads up to knocking off the climax of “The Raiders of the Lost Ark” with surprisingly cheesy effects that are in no way 28 years better than that classic.

Thankfully, neither Gyllenhaal nor Arteton take this nonsense any more seriously than absolutely necessary, and they almost make you believe they have chemistry together. Anyone expecting much in the way of romance, though, will be disappointed: As I noted, this rather chaste movie seems to be aimed at 10-year-olds.

Also helping to make this a fairly painless experience is Alfred Molina, getting most of the laughs as a gold-toothed bandit who occasionally helps the couple and, more notably, runs ostrich races in the desert.

Veteran director Mike Newell (“Harry Potter and the Goblet of Fire”) offers up some handsome desert vistas and vast sets crammed with meticulously detailed costumes and furniture, albeit of dubious authenticity. And he brings it in under two hours, no small accomplishment on a typically overproduced Bruckheimer opus.

“Prince of Persia” got the go-ahead from an administration at Disney that was sent on its way last year. I wouldn’t be surprised if their successors at the Mouse House wish they had a magic dagger that would allow them to go back and erase this movie.

lou.lumenick@nypost.com