She is a 39-year-old mother of three whose first novel spawned an entertainment empire worth billions in only five years.

He is a 49-year-old military officer who was the world’s first action figure and has since generated a brand under his name that goes beyond the toy aisle into comic books, TV and movies.

This weekend, “The Host” and “G.I. Joe: Retaliation,” the latest projects involving, respectively, author Stephenie Meyer and American hero G.I. Joe, will face off at the box office. Yet despite their large, built-in audiences, this battle of entertainment icons doesn’t have a clear path to victory.

“The Host” is a sci-fi romance that adds a twist to the “Invasion of the Body Snatchers” with a complicated love triangle. As Meyer’s first foray outside the fan frenetic “Twilight” universe, it’s unclear how Twihards will react to a movie without their beloved Bella, Edward and Jacob. “The Host’s” attractive young cast is led by Oscar nominee Saoirse Ronan (“Atonement”), Jake Abel and Max Irons.

“G.I. Joe: Retaliation” is opening after a troubling nine-month delay from its original June 2012 release. The fact that it was made at all surprises some after 2009’s “G.I. Joe: The Rise of Cobra” took a drubbing from critics and fans.

When it comes to “Cobra,” Joe Reboy of Tonawanda doesn’t mince words. “It was terrible. It was a massive disappointment,” says Reboy, who started collecting the 12-inch G.I. Joe action figures as a “real little kid,” then watched the cartoons in the early ’80s and picked up his interest again later. “By the time I was in my car on the way home from the movie, I was making jokes about it. It may have had the characters, but not the heart.”

But early footage of “Retaliation” – plus the star-studded cast of hot box-office commodity Channing Tatum, Dwayne “The Rock” Johnson and Bruce Willis – is enough to have Reboy making plans to see the film this weekend.

“No question about it,” he says. “The trailer for the new film is encouraging. It looks like the characters are much more in the spirit of the cartoon and taking the fight back. It seems an about-face from the first film and an acknowledgement from the studio that ‘we dropped the ball.’ ”

Larry Tetewsky of Kenmore will be there as well. “I am committed to seeing ‘G.I. Joe’ on opening night,” he says, adding he sees similarities to the recent animated series, “G.I. Joe: Renegades” with its small covert group of Joes seeking vindication. “This second movie actually seems closer to the animated series, closely mirroring the plot and context.”

Also planning a movie outing this weekend – but to see “The Host” – is Alyssa Grzebinski, 23, of Buffalo, who has read all four “Twilight” books and seen the five films. “It looks interesting and it helps that it was written by Stephenie Meyer,” she says about the film.

“Twilight” fan Andrea Horowitz, 31, of Kenmore has also read and seen everything “Twilight.” She originally read “The Host” because it was written by Meyer and was surprised at how much she liked the story.

“I think she’s a good author. ‘The Host’ stands on its own, and I wasn’t sure that it would,” Horowitz says. “It has a good story – it’s a different story than I’ve ever read before. I don’t usually like science fiction but this has some sci-fi with just enough romance and excitement that it made it really good.”

Fan interest aside, predicting the box office result for these two movies is difficult, especially with “The Host.”

“We’re not sure what it’s going to do,” says Keith Simanton, managing editor of IMDb.

“It’s a blind spot. It has a Stephenie Meyer fan base, but not the Stephenie Meyer fan base,” Simanton says referring to the “Twilight” universe.

For Simanton, who has seen “The Host” and calls it a “serviceable sci-fi film,” it does have one thing missing from “Twilight”: crossover appeal with guys.

“It’s a harder-edged approach. It won’t rebuff them. It’s not a lot of Bella longing for her lost love in apoplectic state in her room in Forks. It’s a lot more active,” Simanton says. “The irony of it is that it’s a better story than any one of the ‘Twilight’ saga.”

He predicts about a $30 million take for “The Host” and perhaps double that for “G.I. Joe,” which will show in more theaters and have the added financial bump of the extra cost for 3-D tickets. The choice of the two movies will work well for families. “The family of four with the 15-year-old girl and 9-year-old boy can part ways at the entrance of the theater,” he says.

To fans, however, the days leading up to the release of both films still carry that joyful anticipation of moviegoing, as evidenced by Reboy’s faith in what he’ll see with “G.I.: Joe Retaliation”: “This will be the fun film we were deprived of in the first place. I’m really pumped.”