LOS ANGELES - In the U.S., 20th Century Fox is selling the feature film "Gulliver's Travels" as a Jack Black comedy.

Overseas, where Jonathan Swift's classic tome is far more familiar, the film is being sold on the story.

So which is it? And is Black a big enough movie star to carry the day? Is his particular brand of humor right for the character Lemuel Gulliver?

Fox will find out as Gulliver's, rated PG, opens December 25 in 2,546 theaters in the U.S. The 3D family adventure is also making a major push overseas.

The bad news is that Black's last live-action film, "Year One," didn't work. Opening in summer 2009, "Year One" stalled out at $43 million domestically and $19 million overseas.

The good news is that Black has great brand awareness among kids. He's the voice star of the "Kung Fu Panda" franchise, and widely promoted the first film in 2008. He's currently preparing for the release of the sequel in May.

Black's signature live-action film was sleeper hit "School of Rock," which over performed in grossing $81.2 million for Paramount in 2003.

"Gulliver's" has several distinct challenges. Tracking has been sluggish, sparking real concern on the Fox lot. Boys and teenage boys are showing the most interest, but Fox needs to get all members of the family if the film is to work.

Movie also enters a saturated market for 3D PG-rated titles, between "Tron: Legacy," "Yogi Bear," "The Chronicles of Narnia: The Voyage of the Dawn Treader" (also a Fox film) and "Tangled," which is showing great staying power.

"Gulliver's" production budget was $100 million. The 3D conversion cost roughly $12 million.

Fox didn't carry the cost alone. Dune Entertainment and Ingenious were the studio's co-financing partners on "Gulliver's." Dune and Ingenious were Fox's partners on "Avatar."

"Gulliver's" was initially scheduled to open in summer of this year. Fox decided to push back the release to the year-end holidays and converted the pic to 3D.

More recently, Fox decided to open the film on Christmas Day in the U.S., rather than on December 22. Studio did so in order to allow more time for marketing, and to get some distance from other 3D fare.

"Gulliver's" also stars Emily Blunt, Jason Segel and Amanda Peet.