Box Office Preview: 'Ender's Game' Eyeing $25 Million-Plus North American Debut

UPDATED: Overseas, "Thor: Dark Word" begins its assault, grossing just north of $8 million on Wednesday as it opened in the U.K. and France, among a handful of other territories; high-profile openings at the North American specialty box office include "Diana" and doc "Casting By."

Sci-fi epic Ender's Game is poised to win the North American box-office race this weekend with a solid $25 million or more opening, hoping to reverse a disturbing downturn in movie adaptations of young-adult books. Overseas, the film has already opened in the U.K., where it is doing softer-than-expected business.

The big headline internationally this weekend will be Disney and Marvel Studios' sequel Thor: The Dark World, which began rolling out Wednesday in the U.K., France and a handful of other markets, grossing north of $8 million and pacing ahead of the first Thor. On Thursday and Friday, Thor 2, with Chris Hemsworth returning in the title role, opens in a number of other major markets before hitting theaters in North America on Nov. 8.

PHOTOS: 'Ender's Game' Premiere Invades Hollywood With Harrison Ford, Asa Butterfield

Ender's Game, a co-production between Summit Entertainment, OddLot Entertainment and Digital Domain, will need to do substantial business worldwide in order to make up its $110 million budget. The action-adventure is based on the best-selling novel of the same name by Orson Scott Card, whose anti-gay comments have riled many (though he has said Ender's Game isn't a YA property, it has been made widely available in schools).

Directed by Gavin Hood, Ender's Game stars Asa Butterfield, Harrison Ford, Ben Kingsley, Viola Davis, Hailee Steinfeld and Abigail Breslin. The film should be boosted by a run in Imax theaters.

Outside of the Hunger Games and Twilight film franchises, YA properties have struggled at the box office. This year, The Host, Beautiful Creatures and Mortal Instruments: City of Bones all flopped.

Set in the near future, Ender's Game revolves around a young boy (Butterfield) who is recruited by the military to stop an alien race from destroying the world.

PHOTOS: 25 of Fall's Most Anticipated Movies

Ender's Game is a sizeable gamble for Gigi Pritzker's OddLot, which financed much of the movie and dispatched sister company Sierra/Affinity to sell the movie internationally. Last weekend, Ender's Game debuted at No. 5 in the U.K. with just under $2 million, but the film could make up ground as it continues to roll out in additional foreign markets.

Relativity Media and Reel FX's animated 3D pic Free Birds is getting an early jump on Thanksgiving by rolling out now. The movie -- about a pair of turkeys who travel back in time to prevent their kind from becoming the traditional holiday meal -- should benefit from being the only new family entry in the market and hit $20 million in its debut (Entertainment One is distributing in Canada), although Relativity insiders are expecting a figure more in the $16 million to $19 million range. The voice cast is led by Owen Wilson, Woody Harrelson and Amy Poehler.

Free Birds, costing $55 million to make, marks Relativity's first foray into the animation business. The company could use a box-office win after suffering a string of disappointments.

CBS Films' sexagenarian comedy Last Vegas, the weekend's third new nationwide entry, is looking at a more modest opening in the $14 million range. Directed by Jon Turteltaub, the film's high-profile cast -- Robert De Niro, Michael Douglas, Morgan Freeman and Kevin Kline -- should result in strong legs, however. A geezer version of The Hangover, Last Vegas stars four friends in their 60s who travel to Las Vegas for a bachelor party. Mary Steenburgen also stars.

PHOTOS: 'Last Vegas' Premiere

Older moviegoers rarely rush to see a film on its opening weekend. CBS Films believes Last Vegas will serve as strong counterprogramming throughout the month. In August 2012, Hope Springs, starring Meryl Streep and Tommy Lee Jones, opened to a modest $14.7 million on its way to earning $63.5 million domestically and a hearty $114.3 million globally.

The specialty box office sees a number of high-profile debuts, including awards contender Dallas Buyers Club, which Focus Features opens in six theaters in New York and Los Angeles, and Diana, the biopic of Princess Diana starring Naomi Watts. Entertainment One is opening Diana in 38 markets.

Dallas Buyers Club has drawn raves for its performances by Matthew McConaughey and Jared Leto.

Universal also releases Richard Curtis' romantic fantasy-comedy About Time, starring Rachel McAdams opposite Tom Hollander, in the U.S. From Working Title Films, About Time is only opening in 175 theaters domestically. Overseas, the film has grossed $32 million from 40 markets, with 17 countries still left to go.

On the documentary side, Tom Donahue's acclaimed documentary Casting By -- which laments the fact that casting directors are snubbed by the Academy Awards -- opens in one theater to New York. In a rare letter to Hollywood that appeared in the The Hollywood Reporter timed to the film's opening, Woody Allen extolled the work of the casting director he has worked with over the years.