In the near future, robotic Sentinels are programmed to identify and exterminate mutants and their human allies. During a Sentinel raid which kills nearly all the mutants in Russia, Kitty Pryde sends Bishop's consciousness back in time a few months before the attack, however this power can't be used on the recipient indefinitely.
Professor Charles Xavier makes contact with Kitty, meeting her at a remote Chinese temple with other mutant survivors. Xavier explains that the Sentinels were designed by Bolivar Trask, who was assassinated by Mystique in 1973. Her DNA being modified by scientists to create and advance the Sentinel program. Kitty, possessing an ability to send a mutant's consciousness back in time, suggests altering history to prevent Trask’s assassination. While Xavier initially plans to be the candidate, Wolverine volunteers instead since his regenerative powers would allow him to survive the process.
Wolverine awakens in his younger body in 1973. After traveling to the X-Mansion, he discovers the school has been shut down, and the younger Xavier (known as Professor X) can walk, lacking his powers under a specialized serum suppressing his mutant powers. Hoping to reunite with Mystique, Professor X agrees to help Wolverine to bust Erik Lensherr out of his prison cell under the Pentagon, aided by Hank McCoy/Beast and Peter Maximoff/Quicksilver.
Mystique discovers Trask has been experimenting on mutants and plots to assassinate him at the Paris Peace Accords. She is prevented by Professor, Erik, Hank, and Wolverine, but Erik decides to kill her as the surest way to prevent the apocalyptic future. Hank intervenes and exposes himself, Erik, and Mystique as mutants to the world. Trask takes advantage of this event and successfully convinces President Richard Nixon to initialize the Sentinel program.
Erik (now Magneto) obtains his signature helmet to block out Xavier’s psychic powers, and secretly takes control of the constructed Sentinels. Professor X abandons the serum, regaining his mutant power, and communicates with his future self, who inspires him to protect the relationship between mutants and mankind. After using Cerebro to track Mystique, he, Hank and Wolverine take flight to Washington, DC and put an end to her assassination plot on Bolivar Trask.
At a ceremony where Nixon unveils the Sentinels, Professor X, Hank, and Wolverine search for Mystique, disguised as a Secret Service agent. Magneto appears, controlling the Sentinels, and uses the Robert F. Kennedy Memorial Stadium to surround the White House. Hank transforms into Beast and fights a sentinel. Wolverine confronts Magneto, but is thrown way into the Potomac River. Nixon, Trask, and Mystique hide in a safe room beneath the White House, but Magneto rips it out of the building with the intention of killing Nixon.
Back in the future, the Sentinels launch an attack on the X-Men, slaying most of them, including Storm, while Magneto is wounded. Mystique stops Magneto from killing Nixon, but goes to murder Trask. Xavier persuades her to spare Trask, altering history and erasing the Sentinels from existence. Magneto and Mystique both leave, one a criminal, the other a hero. Trask is put behind bars for attempting to sell U.S military secrets to Vietnamese officials.
Wolverine wakes up at the mansion in the present day to find Iceman, Rogue, Colossus, Kitty, Beast, Storm, Jean Grey, Scott Summers, and Xavier all alive. Wolverine speaks to Xavier, aware of the changes in history. Back in 1973, the younger Wolverine is rescued by Mystique, disguised as William Stryker.
In a post-credits scene, an Egyptian crowd is chanting to En Sabah Nur, who telekinetically elevates building blocks to forge pyramids as four horsemen watch on.Hugh Jackman as Logan / Wolverine
A mutant with accelerated healing, heightened animal-like senses, and—in 1973—retractable bone claws; in the future, his skeleton and claws are laced with adamantium in his body, making him virtually immortal. Jackman noted how Wolverine driving the plot in spite of his gruff personality made for interesting story choices, as "if you want someone to go back to take someone’s head off, fantastic, but he’s really got to go back and almost act in parts as inspiration, as mentor, as guide, because he can’t do it all on his own, which is always his preferred method".
James McAvoy and Patrick Stewart as Charles Xavier / Professor X
A mutant pacifist and the world's most powerful telepath. He is also a founder of Xavier's School for Gifted Youngsters, and leader of the X-Men. Singer described the younger Xavier as "a very different beast from First Class'
s feckless playboy. He's a wounded animal, bearded, long-haired, filled with rage at the way the world has treated him". Kinberg said the film was intended to be the story of the younger Xavier beginning to "become the Professor Xavier we know" as Wolverine mentored him.
Michael Fassbender and Ian McKellen as Erik Lehnsherr / Magneto
A powerful mutant who can manipulate magnetic fields. While he had dissents with Xavier due to a wish to prove mutantkind's superiority, they revert to being allies as Erik helps the X-Men battle against Sentinels in the future.
Jennifer Lawrence as Raven Darkhölme / Mystique
A mutant with the shapeshifting ability, and also Xavier's childhood friend and adopted sister. Singer said Mystique "is less innocent, evolved, getting closer to where Mystique was in X-Men 2
". Lawrence had suffered skin irritations from the full body make-up used in First Class
, and the process was changed so from the neck down it would be a bodysuit, whose zipper was digitally removed in post-production. As a result, the make-up process was reduced from eight hours to three. The make-up team at Legacy Effects sculpted Mystique's scales digitally, making them shorter in size and placed in a way that they would accentuate Lawrence's face.
Halle Berry as Ororo Munroe / Storm
A mutant who can manipulate weather and one of the most battle-tested and powerful X-Men. Asked if her pregnancy affected her role, Berry replied, "I wasn't in as much as I was meant to be. My ever-growing belly was posing a constant challenge! What I could do was getting more limited so the role that I play is so different from what it could have been, due to my surprise pregnancy". According to Kinberg, Berry had another scene in the film that was cut because of Berry's limited schedule.
Nicholas Hoult and Kelsey Grammer as Dr. Henry "Hank" McCoy / Beast
A mutant with super-strength, agility, reflexes and enhanced speed. Hoult plays the character in scenes set in 1973 while Grammer makes a cameo appearance as Beast in the future setting. The cameo was added because the writers felt Hoult's Beast was "such a sweet, young character" that audiences would want to learn he survived. Once Grammer learned of this opportunity to return as Beast, a character he had enjoyed playing in The Last Stand
, he called Singer asking to get involved, and was flown from New York in secret to avoid drawing attention.
Anna Paquin as Marie / Rogue
A mutant who can absorb the life force and mutant abilities of anyone she touches. Kinberg wrote a shorter part for Paquin than initially planned because she did not have much time to be on-set. During post-production, Paquin's role was reduced to a cameo after most of her scenes were cut; these scenes were later restored on an alternate version of the film, which was released to home media. According to Kinberg, Rogue was to be rescued by the future Magneto and Xavier to provide the elder characters a mission, "something like Unforgiven
". Eventually the producers felt it was a subplot that did "not service the main story", and reshot scenes to replace them. However, she was still featured in the film's various promotional materials. Paquin later stated that she still had fun making the film and did not mind that the majority of her scenes had been cut from it.
Ellen Page as Kitty Pryde / Shadowcat
A mutant who can pass through solid objects. As the youngest member of the X-Men, she plays an important role in their fight for survival. Singer described Pryde as the prime facilitator and that Pryde's phasing ability enables time-travel to happen. Kinberg, when asked why Pryde is not the time-traveler in the film adaptation of the comic-book story, said, "[If] we tried to follow the original and use Kitty, we had a problem because Ellen is 25 years old and she'd be -20 in the First Class era".
Peter Dinklage as Bolivar Trask
A military scientist and the head of Trask Industries who creates a range of robots called Sentinels, designed to find and destroy mutants. Dinklage said Trask "sees what he's doing as a good thing—[his ambition is] definitely blind and he's quite arrogant. He has striven all his life for a certain respect and attention". He also said Trask is opposed by Richard Nixon. Singer said he is a fan of Dinklage and of the television series Game of Thrones
in which Dinklage stars as Tyrion Lannister, which inspired him to cast Dinklage.
Shawn Ashmore as Bobby Drake / Iceman
A mutant who can create and manipulate ice. Ashmore said about his role, "In the first X-Men
I had to make a rose for Rogue but that was the extent of the character, so it's cool to see over these four movies going from that to X2
—where you sort of see him do an ice wall—and in X3
he finally gets to battle, and in Days of Future Past
Omar Sy as Bishop
A mutant who can absorb energy and redirect it in kinetic blasts. Singer said Bishop, along with Warpath, Sunspot and Blink, are not fresh recruits. He said, "they're more refugees that are living day to day in this hideously ruined world. They don't have much hope in the future. They're on the run and they join forces with the remaining X-Men to try to do this one last attempt at fixing the world".
Evan Peters as Peter Maximoff / Quicksilver
A mutant who can move, speak and think at supersonic speeds. Peters described Quicksilver as "very fast, he talks quick, he moves quick. Everything else is very slow compared to him, it's like he's always at the ATM waiting for the bastard in front of him to finish".
Josh Helman as Major William Stryker
A military officer who hates mutants. Helman was originally chosen to play a younger version of Juggernaut before that character was removed from the script. Brian Cox, who portrayed Stryker in X2
, appears in archive footage.
Daniel Cudmore as Peter Rasputin / Colossus
A mutant who can transform his body into organic steel, which grants him superhuman strength, stamina, and durability while in that form. Cudmore was asked whether he trained for his role, he replied, "I didn't have a ton of time to get film ready for this. A trainer friend of mine from Vancouver put together a quick little workout program for me. Since the role was for Colossus, I was aiming to bulk up a bit and get stronger. I ended up eating a lot more. Because of how much I was eating, I had to eat every 2-3 hours to keep my calories up".
Fan Bingbing as Blink
A mutant who has the ability by creating portals to teleport. Fan said the film was the first of a five X-Men
movie contract she signed with 20th Century Fox.
Adan Canto as Sunspot
A mutant with an ability to project solar energy, create flames and solar-powered strength and flight. To prepare for the role, Canto researched Sunspot because when he was cast, he did not know the level of involvement his character has in the film.
Booboo Stewart as Warpath
A mutant and expert tracker with super agility, reflexes, acute senses and enhanced strength. In preparation for the role, Stewart gained 50 pounds and grew his hair much longer than its usual length.
Additionally, Famke Janssen and James Marsden reprise their roles as Jean Grey and Scott Summers / Cyclops respectively in cameo appearances. Lucas Till reprises his role as Alex Summers / Havok. Evan Jonigkeit portrays Mortimer Toynbee / Toad. Gregg Lowe portrays Eric Gitter / Ink. X-Men comic-book writers Len Wein and Chris Claremont appear as United States congressmen. Michael Lerner plays Senator Brickman. Mark Camacho portrays U.S. President Richard Nixon. Singer cameos as a man with a small film camera as Magneto walks away after Mystique's escape in Paris. In a post-credits scene, Brendan Pedder portrays the ancient mutant, En Sabah Nur.
Producer Lauren Shuler Donner stated in August 2006 that a continuation of the X-Men main film series would require a renegotiation. New cast members of X-Men: The Last Stand were signed, while the older cast members were not. Donner said, "There is forty years worth of stories. I've always wanted to do 'Days of Future Past' and there are just really a lot of stories yet to be told". She later pitched the idea of a fourth installment of the X-Men franchise to director Bryan Singer, following the completion of the 2011 prequel X-Men: First Class. In March 2011, Donner said the film was in "active development at Fox"; she said, "We took the treatment to Fox and they love it... And X4 leads into X5".
20th Century Fox saw X-Men: First Class as the first film of a new X-Men trilogy. Donner compared the franchise plans to the darker, more mature content of the Harry Potter film series. Early reports said Matthew Vaughn and Singer were returning to direct and produce the sequel, respectively. While still attached to the project as a director, Vaughn said, "First Class is similar to Batman Begins, where you have the fun of introducing the characters and getting to know them, but that takes time. But with the second one, you can just get on with it and have a rollicking good time. That's the main difference between Batman Begins and The Dark Knight". Describing the possible beginning of the film, Vaughn said, "I thought it would be fun to open with the Kennedy assassination, and we reveal that the magic bullet was controlled by Magneto". Singer said the film could be set around the civil rights movement or the Vietnam War, and that Wolverine could once again be featured. Singer also talked about "changing history" in an interview with Empire magazine. He said he does not want people to panic about events in the past "erasing" the storylines of the previous X-Men films, as he believes in multiverses, explaining the possibility of certain events can exist equally in the histories of alternate universes.
Kinberg said the main focus of this film was the future of the X-Men film series. With the use of cast members from the original trilogy and from First Class, they needed to decide the sequels' destination. In preparation for the film, Kinberg studied films about time travel, including Back to the Future, The Terminator, and Terminator 2: Judgment Day. Singer originated a philosophy and a set of rules for the time travel in the film so the story would be as plausible as possible.
According to Kinberg, as they were writing the script, they thought it is sensible that Wolverine was traveling between time periods, because of his ageless look and ability to heal rapidly. He further stated of making Wolverine the time traveler, "We made the decision for a lot of reasons ... he's the protagonist of the franchise, and probably the most beloved character to a mass audience". Kinberg and Vaughn considered Bishop and Cable candidates for the role of time traveler. Kinberg said Rachel Summers was in the first draft of the script; she sent Wolverine back to 1973. The character was later replaced with Kitty Pryde, to whom Kinberg gave a secondary power of sending people's consciousnesses into the past. Juggernaut, Jubilee, Nightcrawler and Psylocke were also considered for the film.
Singer was asked how the film integrates the themes of the earlier X-Men films; he said, "It establishes that some villain characters may have been right with their fears. It confronts the notions of hope and second chances. It's characters that are lost trying to find themselves. In X-Men 1 and 2, the characters had come into their own and knew who they were. In this one, they're all lost and they're trying to keep it together".
In November 2011, Simon Kinberg—co-writer of X-Men: The Last Stand and co-producer of X-Men: First Class—was hired to write the film's screenplay. In May 2012, 20th Century Fox announced the film would be released on July 18, 2014. The release was later moved forward to May 23, 2014. In August 2012, the title for the film was confirmed to be X-Men: Days of Future Past. The film is inspired by Chris Claremont and John Byrne's X-Men comic book storyline, "Days of Future Past", which introduced the idea of an alternate future for mutants that grew from the Brotherhood of Evil Mutants' killing of a senator, leading to a future in which mutants are hunted by Sentinels.
In October 2012, Vaughn left the role of director to focus on Mark Millar's Kingsman: The Secret Service (2014). Singer was later announced as the film's director; it was his third directorial role in the X-Men film series. In preparation for the film, Singer approached James Cameron to discuss time travel, string theory and multiverses. In the same month, Richard Stammers was approached to be the visual effects supervisor, as Singer liked his work in the 2012 film Prometheus.
Singer brought back most of the crew he had in X-Men, X2. In December 2012, two long-absent designers were hired: production designer John Myhre, who had only done X-Men, and costume designer Louise Mingenbach —who also did X2 and X-Men Origins: Wolverine. In February 2013, John Ottman—who aside from X-Men, collaborated on all of Singer's works since the 1995 film The Usual Suspects—was confirmed to work on the music and the editing of the film.
Singer used the online social networking service Twitter to announce casting of the film. In November 2012, he announced that James McAvoy, Michael Fassbender, Jennifer Lawrence and Nicholas Hoult would reprise their roles from X-Men: First Class. Later the same month, he announced that Patrick Stewart and Ian McKellen would reprise their respective roles as the older versions of the characters played by McAvoy and Fassbender. In December, Singer announced that Hugh Jackman would reprise his role as Wolverine.
In January 2013, Singer announced that Anna Paquin, Shawn Ashmore, and Ellen Page would reprise their roles of Rogue, Iceman, and Kitty Pryde. In February, Singer announced that Peter Dinklage would star in the film as the main antagonist. In March, Singer announced that French actor Omar Sy had joined the cast. Halle Berry said in an interview that she would reprise her role as Storm, which was followed by an announcement from Singer that Berry would be in the film. Singer tweeted a picture of the cast, which confirmed that Daniel Cudmore would return as Colossus and that Fan Bingbing and Booboo Stewart had joined the cast.
In April, Singer announced that American singer and songwriter Lady Gaga had joined the cast as Dazzler, but it was later revealed as an April Fools' Day prank. Singer retweeted a photograph of himself, Adan Canto, and confirmed cast members Patrick Stewart, McKellen, and Ashmore, which was followed by a confirmation from Canto that he had joined the cast. In May, Singer announced that Evan Peters had been cast as Quicksilver. In June, Australian actor Josh Helman was cast in a role. In July, Singer tweeted a picture of actor Lucas Till on the set of the film, which confirmed that he was returning as Havok. In January 2014, Evan Jonigkeit had been cast as the younger version of Toad.
X-Men: Days of Future Past had a production budget of $200 million. Principal photography began on April 15, 2013, at Mel's Cité du Cinema in Montreal, Canada, and ended on August 17, 2013. Filming had to begin in April 2013 to accommodate the cast's individual schedules. Olympic Stadium, Montreal City Hall, and McGill University were also used as filming locations. An aerial plate unit was sent to film in Washington, D.C. Additional filming took place in Montreal in November 2013 and February 2014. According to the Calgary Herald, the film is the second most expensive produced by 20th Century Fox after Avatar (2009). Comic book writer Chris Claremont said in an interview that he was consulted for the film.
X-Men: Days of Future Past is the first X-Men film to be filmed in native 3D; it was shot using Arri Alexa-M cameras with Leica Prime lenses and Fujinon Zoom lenses, along with 3ality Technica TS-35 camera rigs and Stereo Image Processor (SIP) technology systems. Director of photography Newton Thomas Sigel was asked about using Arri Alexa-M cameras; he said, "For Bryan and myself, the Alexa has been almost the gateway to getting the look we like in film". Sigel added that the Arri Alexa-M camera's small size was a big advantage to the film's main unit, which carried three 3D rigs. The film also used the Alexa XTs for the production's 2D work.
Production designer John Myhre said his work load was "six months squeeze[d] down in to 3-4 months", given the sets were massive but he did not have the usual time to design and build before principal photography began. The lue underground hallways and Cerebro sets were faithful recreations of the sets seen in the first X-Men, albeit ransacked and damaged to imply the government had raided the mansion. The sets had many hidden "Xs", including the staircase of the X-Mansion. Myrhe said he wanted to embrace the 1970s setting in the same way First Class embraced its 1960s setting, and costume designer Louise Mingenbach also drew heavily from 1970s styles for the clothing seen in the 1973 scenes. Hoult wore corduroys, Jackman a wooden-paneled buckle and a peacock-print shirt, and McAvoy wore a brown leather jacket. Peters wore 1981-inspired clothing; this was Mingenbach's way of showing Quicksilver's irreverence for the exact time and place. In one scene, Mingenbach gave Fassbender as the younger Erik Lehnsherr a fedora as a nod to the one the character wore in the first X-Men film. For the future period of the film, Mingenbach wanted a darker, slightly futuristic and tactical look for the characters. This included changing the suit Patrick Stewart had previously worn as Xavier to battle fatigues.
The Sentinels had two separate versions, to depict how the earlier prototypes built by Trask in the 1970s evolved into the adaptable killing machines of the dystopian future. Singer described the 1973 version as "a little fun and stylish but also a little retro", with a key element being that they are made of plastic to be unaffected by Magneto's powers. Myhre used styles from molded plastics from the 1970s to design Sentinels from that period, and cited inspiration from both the cars of the decade and "those wonderful TV sets that were round with smoked glass panels". The overall style was bulky to fit "the traditional idea of a robot looks like", and drew the most from the comics version, such as the purple color and a humanoid shape, while trying to stand out on its own with its retro design. The robots' ability to fly was compared to a Harrier Jump Jet, as the Sentinels had vertical takeoff and could glide. Life-sized Sentinels were built by Legacy Effects to be featured on the set, and had articulated joints to be fully poseable. The sound effects averted metallic noises, while adding woof effects on the Sentinels' footsteps to display its weight on the ground.
On the other hand, the future Sentinels would resemble "giant versions of Mystique" to show how their technological development was based on studying the shapeshifting mutant's DNA. Thus their design is sleek and feminine, with a body covered in mechanical scales that move during the process of adapting to a mutant's attack, while also featuring angular and dark faces to enhance the intimidation. The future robots would feature what Singer described as "biomechanical technology to transform to adapt to other mutants, to take on their physicality and some of their powers to use against mutantkind", which the director imagined to be fueled by nanotechnology and "the ability to really change things almost at a molecular level". The Sentinels' heads would also open up as an extra weapon, and for straighter combat the robots could create blades and spikes out of their limbs. The crackling sound of the robots' scales was made by rubbing riveted belts on shale rocks.
For the future setting of the film, a set featuring a hillside monastery was built. Myhre was inspired by Chinese temples built on the sides of cliffs. The future set also featured a mixture of architectural styles from China, India, and Indonesia. Part of the set was a big wall, which was inspired by the Great Wall of China.
X-Men: Days of Future Past had 1,311 visual effects shots produced by twelve studios. Richard Stammer served as the overall effects supervisor based on his work for Prometheus. The leading company was Moving Picture Company, who created the future Sentinels and worked on the sequences involving the X-Jet and Cerebro's red virtual world. The Sentinels' scaled bodies were created by adapting a tool originally developed to create hair and fur, which would later evolve into creating a proxy representation of each individual scale as a "follicle". Another major contributor was Digital Domain, with effects from the 1973 portion that encompassed nearly a third of the work. These included the Sentinels, Mystique's transformations and eyes, and various digital environments. Digital augmentation turned a remote airstrip into a Vietnam prisoner camp and added Paris' famed mansard rooftops to the Montreal locations. The environment work based on Washington, D.C. required the team to study period references of the National Mall and White House, and photograph almost all of RFK Stadium to create a detailed digital replica. Rising Sun Pictures created a sequence considered by many reviewers the centerpiece of the film's effects, where Quicksilver uses his super speed in the Pentagon kitchen. Depicting how, to a speedster, actions in real time come down to a virtual standstill, objects float around in slow motion. After doing LIDAR scan of the kitchen set, the digital recreation added many computer generated props - cooking gear, cutlery, vegetables and water released by a fire sprinkler system - rendered in near microscopic detail regarding placement and lighting, particularly because the footage had to work in 3D. To simulate Quicksilver running on the walls, Evan Peters and a stunt double were filmed in both the set being suspended by a harness and on a treadmill that stood in front of a chroma key green screen. Only Peters' legs were digitally replaced. Despite the sequence only having 29 effects shots, it required nearly seven months of work from RSP's team of 70 artists.
Rhythm and Hues Studios worked on Beast's transformations, the creation of Xavier's plane, and speed effects for Quicksilver. They also worked with Digital Domain on the sequence featuring the inside of the 1973 Sentinel. Mokko Studio worked on Mystique's eyes and costume fixes. Cinesite worked on the future New York City in the opening prologue along with clean-ups, wire removals, and production fixes. Fuel VFX worked on holographic effects and Havok's mutant powers. Vision Globale worked on visual effects relating to a dream and flashback sequence. Hydraulx, Lola and Method Studios handled a number of compositions and production fixes. The Third Floor worked on extensive story-boarding and visualisation.
Director Bryan Singer’s regular collaborator John Ottman worked on the score of the film, in addition to being its editor. Ottman is the first composer to score more than one film in the X-Men film series, having previously scored X2 (2003). This also marked the first time a theme from a previous X-Men film has been retained; Ottman re-used some of his themes from X2, most notably the main title theme. While Ottman retained the same style of "lyrical and build upon character themes that would weave in and out of the film and done in a straight orchestral sense" that he had used in X2, following Singer's request he tried to compose "something more 'modern'" that could be compared to other contemporary superhero scores, and not follow Henry Jackman' score for First Class. The 1970s setting inspired the inclusion of "synthesized elements with some analog synths and electric piano and bass and some guitar". The film score was released on digital download on May 16, 2014, on CD on May 26, 2014, and on vinyl on August 4, 2014. The Rogue Cut also got a soundtrack album, released on July 10, 2015, by Sony Classical Records.
The world premiere of X-Men: Days of Future Past occurred at the Jacob K. Javits Convention Center in New York City on May 10, 2014. It was released in international markets in 2D and 3D theaters on May 21, 2014, and in the United States on May 23, 2014. Premiere events were also held in London, Beijing, Moscow, Singapore, São Paulo, Melbourne, and Tokyo.
In June 2013, 20th Century Fox presented a set tour video of X-Men: Days of Future Past at the CineEurope conference in Barcelona; director Bryan Singer acted as the tour guide. The set tour video was included with the home video release of the 2013 film The Wolverine. In July 2013, Singer, writer Simon Kinberg, producers Lauren Shuler Donner and Hutch Parker, together with cast members Evan Peters, Omar Sy, Ellen Page, Shawn Ashmore, Anna Paquin, Halle Berry, Ian McKellen, Patrick Stewart, Hugh Jackman, James McAvoy, Michael Fassbender, Jennifer Lawrence, Nicholas Hoult, and Peter Dinklage presented at the 2013 San Diego Comic-Con International. Footage from the film was screened. In August 2013, Singer presented footage from the film at the Fantasia International Film Festival. In March 2014, 20th Century Fox presented footage from the film at CinemaCon. In April 2014, Page presented footage from the film at the 2014 MTV Movie Awards. Kinberg and Dinklage attended WonderCon to discuss the film. Singer withdrew from the publicity rounds for the film because of a lawsuit alleging sexual abuse filed against him. In July 2014, 20th Century Fox and Oculus Rift presented a "virtual reality experience" in 2014 San Diego Comic-Con International. Attendees were given a chance to sit in a replica of Professor X's wheelchair and virtually hunt Mystique in the San Diego Convention Center.
In July 2013, a mid-credits scene teasing X-Men: Days of Future Past was attached to the theatrical release of The Wolverine. The scene, set two years after the events of The Wolverine, depicts Wolverine going through an airport security checkpoint while a commercial for Trask Industries plays in the background. Suddenly, Wolverine notices that all the metal objects around him start to shake and levitate. He turns around to see Magneto, who says he needs Wolverine's help to combat a threat to all mutants. When Wolverine asks Magneto why he should trust him, the people around them freeze as Xavier approaches Wolverine and assures him that Magneto is telling the truth. Adam Pockross of Yahoo! Movies described the mid-credits scene as the coolest part of The Wolverine and wrote, "Boom! And that's how you tease the next film: by giving us so much to chew on, yet so few answers".
The first official trailer for X-Men: Days of Future Past was released in October 2013. Jason Callina of Herald News gave the trailer a positive response, saying, "it is fantastic to see characters that I grew up with in the flesh ... we still have to wait till the end of May to see if Fox succeeded, but for now they have my interest". Ben Child of The Guardian criticized the trailer for the amount of characters that will appear in the film. Child wrote, "overloading the movie with superheroes might please fans of the comic books, but the rest of us will be chewing on our own spleens when the umpteenth brightly coloured dude turns up to spout one line of dialogue, then drop off the map".
A mid-credits scene teasing X-Men: Days of Future Past was attached to the theatrical release of The Amazing Spider-Man 2 in April 2014. In the scene, which is set during the Vietnam War, Mystique tries to infiltrate a military camp led by William Stryker to recruit fellow mutants Havok, Ink, and Toad. The Amazing Spider-Man 2 director Marc Webb had an existing contract with Fox Searchlight Pictures to direct another film following 500 Days of Summer (2009). After The Amazing Spider-Man, Webb's negotiations with Sony Pictures Entertainment stalled because of his commitment to Fox. Fox eventually agreed to allow Webb to direct the sequel of The Amazing Spider-Man, and in exchange, Sony promoted the X-Men film without charge. In addition, three viral websites were launched before the release of the film—Trask-Industries.com in July 2013, TheBentBullet.com in November 2013 and 25Moments.com in April 2014. To further promote the film, Jackman made a guest appearance on the April 28, 2014, episode of WWE Raw. The segment received mixed reactions.
In July 2013, CKE Restaurant Holdings, Inc. and 20th Century Fox announced a promotional partnership for the theatrical release of X-Men: Days of Future Past. The promotion included advertising, in-restaurant merchandising, collectors' cups, and a film-themed burger—The Western "X-Tra" Bacon Thickburger sold it CKE Restaurants outlets Hardee's and Carl's Jr.. Zachary Eller, senior vice president of marketing partnerships & promotions at 20th Century Fox, said, "their fun and irreverent advertising campaigns are a great fit with our film and we couldn't be more thrilled to join together to feed mutants everywhere!".
Mountain Dew partnered with the film to promote it globally; the promotion included prizes, a television commercial, online exclusives, in-store and in-theater advertisements, and commemorative packaging featuring X-Men characters from future and past. Anna Roca, senior vice president of international promotions at 20th Century Fox, stated, "The adventurous, energetic attitude of [Mountain Dew's] fan base mirrors the franchise's own—and their international reach helps bring our beloved mutants to more corners of the world than ever before".
In March 2014, Virgin Trains launched an 11-car Pendolino train, which featured the film characters on the carriages, at London's Euston station to promote the film. Hugh Jackman and James McAvoy attended the launch.
Kia Motors collaborated with 20th Century Fox to promote the home media release of the film with a Wolverine-themed Sorento. The SUV made its debut at the 2015 Australian Open, with a series of videos featuring Rafael Nadal teaming up with the X-Men to save the tennis event from the Sentinels.
In June 2014, cable network FX acquired the television rights to X-Men: Days of Future Past. The film was released by 20th Century Fox Home Entertainment on digital download on September 23, 2014, and on DVD, Blu-ray and Blu-ray 3D on October 14, 2014. In the United Kingdom, it was released on November 10, 2014. Three versions were released; a Deluxe Edition containing the Blu-ray 3D, Blu-ray and digital download; a Blu-ray and digital download combo pack; and a single-disc DVD.
20th Century Fox Home Entertainment released an alternate version of the film, titled The Rogue Cut, on July 14, 2015. It added 17 minutes of previously unused footage, including a subplot involving Anna Paquin's character Rogue, whose role was reduced to a brief cameo in the theatrical release. The Rogue Cut was also screened at the 2015 San Diego Comic-Con International.
In the Rogue Cut version, Rogue's role is more consequential, and the narrative is more complex: When seeing Stryker causes Wolverine's consciousness to phase between past and future—resulting in his claws being extended, injuring Kitty Pryde—the Professor talks about the need for Wolverine to have more time back in 1973. Bobby Drake (Iceman) proposes breaking into the heavily guarded remains of Cerebro at the Professor's school, the one place where the Professor's mind can't reach others from the outside, in order to rescue Rogue, who is being held captive there. With the Professor and Magneto, he does so—at the cost of his own life—and Rogue is taken to where the mutants are making their last stand, where she takes over for Kitty in regards to keeping Wolverine's mind in 1973, for the remaining time until the moment history is changed, with a suggestion that Wolverine is aware of the switch as he appears to feel Rogue's presence. The Sentinels were able to find the X-Men through a tracking device inside a Sentinel's hand, which got stuck in the X-Jet after the Sentinel tried to prevent the Professor, Magneto and Rogue from escaping the incinerated remains of the X-Mansion. It also includes another scene where Mystique visits the X-Mansion at night while Charles and Logan are sleeping. She revisits her previous romance with Beast but leaves very early the next morning and breaks Cerebro in order to prevent Charles from finding her.
The Rogue Cut also includes a mid-credits scene, where the Pentagon prison is shown to be repaired with a new inmate Bolivar Trask, who was arrested for selling military secrets to foreign countries.
Worldwide, X-Men: Days of Future Past earned $262.8 million during its opening weekend, the highest worldwide opening weekend for an X-Men film. The film grossed $233.9 million in the USA & Canada and $513.9 million in other markets for a worldwide gross of $747.9 million, making it the highest-grossing entry in the X-Men film series before being surpassed by Deadpool two years later.
In the United States and Canada, the film earned $8.1 million from Thursday night showings, which is the highest late night opening for an X-Men film. It was also the highest-grossing film during its opening weekend, earning $90.8 million, which made it the second-highest opening weekend of the series, at the time, behind X-Men: The Last Stand ($102.8 million). During the four-day Memorial Day weekend, it earned $110.6 million. The audience was 56% male and 59% were older than 25.
Elsewhere, the film was the highest-grossing film during its opening weekend, taking $172 million, making it Fox International's highest opening weekend. The film's highest-grossing debuts were in China, South Korea, the United Kingdom, Ireland, and Malta. It was also the highest-grossing debut for a 20th Century Fox film in 11 markets, including South Korea, Brazil, the Philippines, and India. It became the highest-grossing X-Men film in Argentina, Australia, Austria, Belgium, Brazil, China, Colombia, Croatia, Czech Republic, Denmark, Ecuador, Egypt, Finland, France, Hong Kong, Hungary, India, Israel, Italy, Malaysia, Lebanon, Mexico, the Netherlands, New Zealand, Norway, the Philippines, Poland, Singapore, Slovakia, South Korea, Sweden, Thailand, the United Kingdom & Ireland, and Venezuela.
On review aggregator Rotten Tomatoes X-Men: Days of Future Past has an approval rating of 91% based on 284 reviews, with an average rating of 7.6/10. The site's critical consensus reads, "X-Men: Days of Future Past combines the best elements of the series to produce a satisfyingly fast-paced outing that ranks among the franchise's finest installments". On Metacritic, the film has a score of 74 out of 100, based on 43 critics, indicating "generally favorable reviews". Audiences polled by CinemaScore gave the film an average grade of "A" on an A+ to F scale.t
Sean O'Connell of Cinema Blend gave the film four and a half stars out of five, and said it was "the greatest, most complete and staggeringly entertaining [X-Men film] to date". Empire gave it four out of five stars and called it, "The best X-Men film since the second one". Steve Rose of The Guardian rated the film three stars out of five; he said, "Non-devotees might struggle, but director Bryan Singer whips up the action towards a symphonic climax". David Rooney of The Hollywood Reporter said, "While it's more dramatically diffuse than the reboot and lacks a definitive villain, the new film is shot through with a stirring reverence for the Marvel Comics characters and their universe". Justin Chang of Variety said, "If the characters' quandaries at times feel overly circumscribed, they're also advanced with a bracing emotional directness, devoid of either cynicism or sentimentalism, that touches genuine chords of feeling over the course of the film’s fleet 130-minute [sic] running time". In 2016, James Charisma of Playboy ranked the film #8 on a list of 15 Sequels That Are Way Better Than The Originals.
In contrast, Robbie Collin of The Daily Telegraph rated the film two stars out of five and called the plot "a curate's egg, thoroughly scrambled". He concluded, "The film squanders both of its casts, reeling from one fumbled set-piece to the next. It seems to have been constructed in a stupor, and you watch in a daze of future past". Simon Abrams, writing for RogerEbert.com, gave the film two-and-a-half stars out of four, calling it a "visually driven and paint-by-numbers-plot". Abrams was critical of the undeveloped subplots that built up because the film's pacing left little time to develop each element of the story set in the 1970s.
In December 2013, Singer announced X-Men: Apocalypse, an X-Men film acting as a sequel to X-Men: Days of Future Past. Singer directed from a script by Simon Kinberg, Dan Harris, and Michael Dougherty. Kinberg said it would take place in 1983 and would also complete a trilogy that began with X-Men: First Class. Released in 2016, Apocalypse features the ancient mutant En Sabah Nur, who was introduced in the Days of Future Past post-credits scene, awakening in the 1980s and deciding to destroy modern civilization and take over the world. Jennifer Lawrence, James McAvoy, Michael Fassbender, Nicholas Hoult, Evan Peters, Rose Byrne, Lucas Till and Hugh Jackman reprise their roles. Filming began in April 2015 in Montreal, Quebec for a May 27, 2016, release.