The studio has thrown an estimated $250 million behind the flick, and a strong performance can buoy Fox after a string of big budget disappointments.
The same could be said of 20th Century Fox, the studio releasing the film.
Fox is pinning a lot on its latest X-Men film. The studio that set an all-time record with "Avatar" in 2009 has since floundered, turning out a series of big budget duds and box office middleweights. In a cinemascape now dominated by comic book adaptations, Fox is betting the mutants that helped start the superhero trend 14 years ago will come to its rescue today.
"It really needs to be one of the top five films of the summer, in terms of grosses. And that's just the bottom line," said Jeff Bock, senior box office analyst at Exhibitor Relations Co. "It has to succeed on a major level."
With an estimated budget of $250 million, "X-Men: Days of Future Past" could be the most expensive movie Fox has ever produced-more expensive than "Avatar," which Fox made for $237 million, and pricier than Disney's "The Avengers."
Both of those films earned their keep. "Avatar" took in nearly $2.8 billion worldwide, while Avengers netted Disney a cool $1.5 billion. The highest gross for any movie in the six-film X-Men franchise is $459 million.
This time could be different.
The market for superhero films is much larger than it was in 2006 when the first X-Men trilogy wrapped up. The 2011 prequel "X-Men: First Class" breathed new creative life into the franchise and locked in rising stars Jennifer Lawrence, Michael Fassbender and Nicholas Holt.
Reviews for "X-Men: Days of Future Past" ahead of the long Memorial Day weekend release are overwhelmingly positive. The film is a shoo-in for a $100 million-plus weekend, Bock said.
"As long as it does do that, Fox has got to be happy because that means it's doing at least that much if not more overseas," Bock said.
Those overseas markets now determine whether superheroes sink or soar, another change from 2006. This year, foreign demand remains strong. As of last weekend, "The Amazing Spider-Man 2" earned $461 million overseas, and "Captain America: The Winter Soldier" reached $452 million.
That formula has worked for the X-franchise, too. Last year, "The Wolverine" did a respectable $132 million domestically, but foreign sales drove the global take to $414 million. Four years earlier, Wolverine's first film outperformed at home with $179 million but only reached $373 million worldwide.
"The Wolverine" capitalized on the growing Asian market with a story entrenched in Japanese culture. China was it's biggest foreign market with $40.5 million. "X-Men: Days of Future Past" can lean not just on Wolverine's popularity in the Middle Kingdom, but the casting of Chinese superstar Fan Bingbing as mutant heroine Blink.
Still, the perceived success of "The Wolverine" was due in part to its moderate budget. Fox has lately failed to convert huge capital expenditures into profits.
Fox's filmed entertainment division accounted for about 20 percent of 21st Century Fox's revenue in the first nine months of the fiscal year. Within that segment, executives have pointed to strength in television production business, but say lower sales at theaters and higher release costs have led to disappointing film results.
High-priced disappointments such as "The Secret Life of Walter Mitty" have contributed to Fox's underperformance. "X-Men: Days of Future Past" will likely be Fox's first $200 million plus domestic opening since "Avatar."
Last year, five Disney films did better than $200 million domestically. Warner Bros. had three, and five more films exceeded $100 million.
On the global stage, just three new Fox films have exceeded $500 million since 2010: "Ice Age: Continential Drift," Dreamworks' "The Croods," and "Life of Pi."
In that light, the high price of the "X-Men: Days of Future Past" might be best viewed as an investment in the future of the franchise, Bock said.
Fox has already scheduled an X-Men sequel for 2016 and a third Wolverine film for the following year. It has announced planned spinoffs, including one featuring X-Force, a darker, militaristic cadre of mutants in the comics.
It's also injecting star power into the franchise. Producer Lauren Shuler Donner announced at the U.S. premiere that Channing Tatum will join the cast of "X-Men: Apocalypse" in 2016 in the role of fan-favorite Gambit. On the Australian red carpet, Hugh Jackman told IGN he was less sure he would leave the franchise as planned, saying the series feels fresher than ever.
Mutants won't be the only heroes in Fox's universe, either. The studio will take a second crack at its "Fantastic Four" franchise next year, rebooting the exploits of the super-powered family of space explorers.
The excitement Marvel has generated around its brands following the successful Avengers films could give the X-Men and Fantastic Four a boost. But the movies have also set a high bar, and though the Marvel characters are allies in the comics, they're bitter rivals at the box office. Were either Fox franchise to fail, the silver lining might shine brightest on Marvel.
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"Those rights mean you have to make those movies, otherwise they revert back to Marvel. And in this case that means Disney," Bock said. "So you're giving it right back to your competitors. Certainly you don't want to do that."
Other films could make it a turnaround year for Fox. Dreamworks' "How to Train Your Dragon 2" has little animated competition this summer. "Dawn of the Planet of the Apes" is another sequel with a successful predecessor.
"The Fault in Our Stars," based on a young adult romance, could attract women given the dearth of female-skewing films this summer, said Bock, but "Maze Runner" will struggle, as have other dystopian YA adaptations beyond The Hunger Games series.
In October, Fox releases a screen version of best-selling book "Gone Girl" starring Ben Affleck and directed by David Fincher, the hit-maker behind "House of Cards" and "The Social Network."
-By CNBC's Tom DiChristopher.