Production of Avengers: Infinity War and the untitled Avengers sequel

Development

Starting with their early films, Marvel Studios began planting the seeds for an Avengers film that adapted the Infinity Gauntlet comic arc, by introducing the powerful Infinity Stones as MacGuffins: the Space Stone as the Tesseract in Captain America: The First Avenger; the Mind Stone inside Loki's Scepter in Marvel's The Avengers; the Reality Stone as the Aether in Thor: The Dark World; the Power Stone as the Orb in Guardians of the Galaxy; and the Time Stone within the Eye of Agamotto in Doctor Strange. Additionally, two Infinity Gauntlets, gloves designed to house the stones, are briefly seen in Thor and Avengers: Age of Ultron, the latter in the possession of the villain Thanos, who covets the stones in the comics. Many fans expected Thanos to be the antagonist of the second Avengers film after making a brief appearance at the end of the first, but Joss Whedon, the writer and director of the first two Avengers films, explained that "Thanos is more powerful. He is so powerful, he is not someone you can just try to out punch. Like in the comics, you want him to be threading through the universe and to save the big finale for the big finale."

While all non-Avengers films in the MCU were considered set-up for this storyline, laying "much of the groundwork", producer and president of Marvel Studios Kevin Feige said that Black Panther in particular would be "a very important" link to the Avengers sequels in Phase Three of the MCU, as was Thor: Ragnarok. The sequels were described as "the culmination of everything that has happened in the MCU" since Iron Man was released in 2008, bringing "an end to certain things, and in some ways... the beginning of certain things."

In June 2013, Robert Downey, Jr. signed on to return as Tony Stark / Iron Man for a third Avengers film, and Josh Brolin signed a multi-film deal the following May, to play Thanos. In July 2014, Feige stated that there were "some notions" to where Marvel would want to take a third Avengers film and that actors from previous MCU films were under contract to return. He also said that the studio was aiming for three years between Avengers: Age of Ultron in 2015 and a sequel. In September 2014, Jeremy Renner confirmed he was signed on to reprise the role of Clint Barton / Hawkeye in a third Avengers film.

In October 2014, Marvel announced a two-part sequel to Age of Ultron, titled Avengers: Infinity War. Part 1 was scheduled to be released on May 4, 2018, with Part 2 scheduled for May 3, 2019. After the announcement, Feige talked about the scale of the film and the possibility of the characters from Marvel Television's Netflix Defenders series appearing, saying, "Infinity War is going to be big. There are a lot of people from the movies in Infinity War. A lot of it is about space, and a lot of it is about just what happens between now and then. But all of those things inhabit, however far on the outskirts, the same continuity. So certainly that opportunity exists." Feige also mentioned that Mark Ruffalo would return for Infinity War, reprising his role as Bruce Banner / Hulk, while Downey and Brolin were clarified to be appearing in both parts of the film. In November, it was reported that Avengers: Infinity War – Part 1 and Avengers: Infinity War – Part 2 were scheduled to begin filming back-to-back in late 2015, and Tom Hiddleston signed on to return as Loki for both parts.

In January 2015, Whedon stated that he was "very doubtful" that he would be involved with the two Infinity War films. By April, Anthony and Joe Russo reached a deal to direct both parts of Avengers: Infinity War after directing the latter two Captain America films, with filming expected to begin in 2016. Whedon cited the series' increasing scale as to why he chose not to return, explaining, "Every movie I have ever made has been an ensemble piece of increasingly enormous proportions... That many balls in the air, it's only going to get bigger with Infinity War. I'm not going to be able to give it what I would need to." Feige said that "because they [have] such shared elements, it felt appropriate... to [subtitle the films] like that. But I wouldn’t call it one story that's cut in half. I would say it's going to be two distinct movies." Anthony Russo reiterated that the two Infinity War films were "very very different from one another. It’s not a part one and part two scenario, necessarily. They’re just two different expressions. I think it creates a misconception that we’re shooting them at the same time." While promoting Age of Ultron, Chris Hemsworth, who plays Thor, revealed that he and Chris Evans, who plays Steve Rogers / Captain America, both had the two parts of Infinity War on their contracts. Scarlett Johansson, who plays Natasha Romanoff / Black Widow, said it was "too early to say", but believed she would be involved with at least one of the films. At the end of April, Evans revealed that filming was scheduled to begin in late 2016 over nine months, lasting until August or September 2017.

By May 2015, Christopher Markus & Stephen McFeely signed on to also return from the Captain America films, writing the screenplays for both parts of the film. The pair began work during the filming of Captain America: Civil War "as soon as they start[ed] shooting [when] we don't have much to do for the next six hours," McFeely said. "We'd go to the office, read comic books, write down ideas, put everything on the wall and just go 'These are all the characters we could have.'" Markus added, "We sent in literally 60 pages of unrelated ideas. Just like 'Here's some stuff that could happen in this insane movie.' Then we came back from Atlanta and everyone had a copy of that [document] and they'd circle this, 'This is cool, this is insane, this is cool, we're not allowed to do that,' and from there [we] pieced it together very slowly." That month, William Hurt expressed interest in appearing in Infinity War as his character Thaddeus "Thunderbolt" Ross. In September, Feige said the films would explore the visions the Avengers had in Age of Ultron, saying going forward, "were those little visions? Is that kind of like your worst fears being projected at you? Is that a prediction of the future? Or is that a sense of an ending doom that haunts you and keeps you awake at night? I think that'll be something we have to explore in Infinity War to kind of figure out how literal or not those are." In December, Anthony Russo stated that integrating characters from the MCU television series into Infinity War would be "complicated", due to the series' serial nature of storytelling, and the fact that, despite all existing in the MCU, Feige controls the films under Marvel Studios, and the television series are controlled by Marvel Television, with separate oversight.

Pre-production

In January 2016, the Russos stated that they were "breaking ground" on the films, and Joe highlighted their large scope, saying that the audience would "not be disappointed in the amount of characters" featured in the films, adding that they had a character board showing all previously introduced and available MCU characters "with like 67 characters on it." Markus and McFeely clarified that having that many characters available to them did not mean that all would appear in the films or be lead roles, and also noted the board did not include any potential new characters. On whether choosing the characters to appear in the film were personal preferences or dictated by the story, Anthony Russo said, "It's a little bit of both, because you always have to make sure that your choices feel organic to the storytelling, and really, you have to sort of structure them in the way that they need to be there... It's a little bit of a dance between the two, where you have big eyes, and you want everybody included in the movie, but you have to go through the process of... what's the best story that you can tell."

Joe Russo described the concept as "the Marvel universe [uniting] to battle the greatest threat to the world and universe that you’ve ever seen". He noted their approach to the cosmic elements of Infinity War would be "with the same fervor that we did the earthbound work we've been doing" and "applying the same rules that we like to apply to the last two films that we've done" (Captain America: The Winter Soldier and Civil War). "We also are going to work really hard to bring a psychological realism. We obviously can't bring a naturalism to it because it doesn't really exist outside of science fiction, but we can bring that psychological realism to it, to the characters, and that's going to be our focus." The Russos revealed that filming would take place in Atlanta, Georgia, beginning in November 2016 lasting until June 2017, and that Markus and McFeely had begun work on the screenplay for the first film.

In February 2016, McFeely called writing Civil War "a walk in the park compared to these" films, noting the fact that they were writing scenes for characters who had not been cast yet. Additionally, Joe Russo said that he and Anthony wanted "a strong through line" from The Winter Soldier to Civil War and into the two Infinity War films, saying, "We look at [Civil War] as setting the stage for Infinity War, how it starts and what condition everybody's in." Joe Russo also expanded about crafting the story of the films with so many characters, saying that they hoped to "focus on a handful of characters" with many of the other characters appearing having "ancillary roles" in order for the story "to be built around the characters' emotional arcs." He also added that the number of characters in Civil War was preparing the brothers to "deal with probably triple the amount of characters in Infinity War". Also in the month, Stellan Skarsgård, who portrays Erik Selvig in the MCU, said he believed he would appear in Infinity War as he had one more film left on his contract, and would not be appearing in Thor: Ragnarok, while Krysten Ritter, who plays Jessica Jones in the Netflix series of the same name, also expressed interest in appearing, saying "it'd be really exciting to be a part of those giant, huge movies with those great characters who are already established, so it'd be awesome ... There's always the chance that could happen." In March 2016, the Russos explained that they were exploring new ways to deliver additional material to audiences for the films, usually reserved for physical home media releases. Given the declining sales for Blu-ray and DVD, Anthony stated, "We’re just in the beginning phases of figuring [this] out. Yes, DVDs are gone but there is this wonderful internet platform out there called YouTube." One example he provided was creating "more elaborate versions of trailers ... that are shot specifically for online that will never appear in the movie but that may appear as a kind of short film." Joe added that the duo were "also talking to Facebook and Twitter and Instagram about ways to feed ancillary content to them and to viewers because it’ll go viral there and you can reach millions of people."

The Russos revealed in April that Chris Pratt would reprise his role of Peter Quill / Star-Lord, one of the Guardians of the Galaxy, in Infinity War, and that Wanda Maximoff / Scarlet Witch would appear as well, while Markus revealed that they were "in the middle" of piecing together the film. The Russos and Markus and McFeely also revealed that they were "talking to the directors and writers of the other Phase Three movies on an almost weekly basis" in order to ensure "everything lines up right." Additionally, Anthony talked about the films being told from multiple perspectives, saying, "You’re going to be moving around through different perspectives of the characters. It’s like Nashville for super heroes. It’s storytelling that is vignetted storytelling. It’s to composite all of them under one story—everybody." The Russos also teased the inclusion of Stephen Strange / Doctor Strange and Carol Danvers / Captain Marvel in the films, though Feige indicated that Danvers was slated to be introduced in her own film, which is scheduled to be released in between the two parts of Infinity War. Markus also talked about how he and McFeely were handling Thanos, a character that the audiences knows is the threat of the films, yet until these films, had little scenes and screen time to divulge his history and motivations. He said, "We don’t get an element of surprise [with his introduction]... You can count on a lot of scenes where we illuminate a lot about him very early [in the first film]," with McFeely adding, "It is incumbent upon us to give him a real story, real stakes, real personality, and a real point of view." Also in April, Samuel L. Jackson believed he would reprise his role as Nick Fury in both parts of Infinity War, and Jon Favreau confirmed he would once again serve as executive producer on the films, having done so on the previous Avengers films after directing the first two Iron Man films.

In early May, the Russos revealed that they would be retitling the two films, to further remove the misconception that the films were one large film split in two, with Joe stating, "The intention is we will change [the titles], we just haven’t come up with [them] yet." Markus also teased the inclusion of additional Guardians in the films. The next month, Alan Silvestri, who composed the score for The Avengers, was revealed to be returning to score both Infinity War films. By late July, Marvel announced that Part 1 would simply be known as Avengers: Infinity War, while Part 2 was referred to as Untitled Avengers film until a title was chosen. Anthony Russo stated that the title of the second film would not be revealed "for quite some time." Pratt was confirmed to be appearing in both films, and Elizabeth Olsen was confirmed to be reprising the role of Maximoff in both films as well. Markus and McFeely also provided an update on the writing of the films that month, saying they were working on the third draft of Infinity War and the second for its sequel, with Markus stating, much like how they would be filmed, "On any given day, you’re only working on one but that doesn’t mean that next week, you aren’t working on the other one."

In August, Sebastian Stan was revealed to be reprising his role as Bucky Barnes / Winter Soldier in Infinity War, while Vin Diesel confirmed he would reprise his role as the voice of Groot, and stated the other Guardians of the Galaxy would appear, in addition to Quill. The Russos also stated they hoped to have another actor from the TV series Community, where the Russos directed episodes, make a cameo appearance, after Danny Pudi and Jim Rash appeared in The Winter Soldier and Civil War, respectively. At the end of September, Benedict Cumberbatch confirmed that he would reprise the role of Strange in Infinity War, and that Paul Bettany would appear in Infinity War as Vision, while Feige confirmed that Cumberbatch would return for the sequel as well. Jackson confirmed he would appear in both films as Fury. In October, Evangeline Lilly, who portrayed Hope van Dyne in Ant-Man, said that her character would not appear in Infinity War, but would appear in its sequel instead, in order to preserve her debut as the Wasp in Ant-Man and the Wasp. Feige announced that filming would begin in January 2017, and Tom Holland, who portrays Peter Parker / Spider-Man in the MCU, said the possibility of him appearing in the films was "all up in the air", but that "some sort of deal is in the mix," since Sony Pictures Entertainment still holds the film rights to the character. Additionally, Cobie Smulders and Benedict Wong revealed they would reprise their roles as Maria Hill and Wong, respectively, from previous MCU films in Infinity War, and Renner was confirmed for both films.

While promoting Doctor Strange, director Scott Derrickson explained that he is "kept in the loop" on how the Avengers films will use Strange because of his close relationships with Feige and Joe Russo, and stated that he had discussed the plot of both Avengers films with Joe "outside the men’s room at Marvel", and had given notes on them, saying, "this is why this is great, this is so the way to do this... [and] no, this is why that’ll never work..." The following month, James Gunn, director and writer of the Guardians films, stated he would be involved with the films, in an executive producer role, stating that he worked with the Russos, Marvel and Feige "to make sure that any of the characters I'm involved with that are in [Infinity War] are well taken care of and are as funny as they should be and is [sic] honest and truthful as they should be." In early January 2017, Zoe Saldana and Dave Bautista confirmed they would be reprising their roles as Gamora and Drax the Destroyer in Infinity War, Peter Dinklage was in negotiations to appear in the films, and Karen Gillan revealed she would appear in both films as Nebula. Production designer Charles Wood also noted the films would be introducing "many, many, many new worlds" outside of Earth and others previously established in prior films. Renner, Olsen, and Bautista noted that the actors appearing in the films had not received scripts before the start of shooting, with Bautista specifically stating on January 22, 2017, that he had not received a script, despite beginning his filming on January 23.

Filming

Principal photography for both films began on January 23, 2017, at Pinewood Atlanta Studios in Fayette County, Georgia, under the working title Mary Lou, with Trent Opaloch serving as director of photography. Additional filming will also take place in locations around the world, including Scotland, with filming to take place in Edinburgh, Glasgow, and the Scottish Highlands, with studio work taking place at Wardpark Studios in Cumbernauld. Filming in Scotland began on February 28, 2017, and is expected to last for six months in the country. From March 18 through April 21, 2017, filming occurred in Old Town, Edinburgh on and around the Royal Mile, including High Street, Parliament Square, Cockburn Street, and Roxburgh Close and Old Fishmarket Close, as well as Waverley Station. The films were shot concurrently, with the Russos stating "some days we'll be shooting the first movie and some days we'll be shooting the second movie. Just jumping back and forth." Regarding the decision to shoot both films this way, Anthony Russo said it made more sense financially and logistically due to the large number of cast members, even though each part is its own distinct film. Filming is expected to last until October/November 2017.

The Russo brothers announced that both films would be shot using IMAX/Arri 2D digital cameras, thus marking the first time that a feature film will be shot entirely using IMAX cameras and its exclusive aspect ratio. The films will be captured on the Arri Alexa 65 with IMAX then digitally processing the footage. Opaloch noted that the production would use 12 of the Alexa 65 cameras, and that Arri was working on lenses with additional focal lengths for the camera, with the hope they would be available by the start of filming since the production would "need all the accessories and lenses" since it was "such a behemoth of a project."

After the start of filming, Sean Gunn revealed he was involved with the films, serving again as the on-set stand-in actor and motion reference for digital character Rocket. He has also previously appeared in the Guardians films as Kraglin, while Pom Klementieff also revealed she would appear in Infinity War, reprising her Guardians role of Mantis. In early February 2017, it was confirmed that Johansson would appear in Infinity War, Brolin revealed that Benicio del Toro would be filming scenes for Infinity War, reprising his role as Taneleer Tivan / The Collector, and Marvel confirmed that Holland would appear as Spider-Man. Jim Starlin, creator of Thanos, Gamora, and co-creator of Drax, indicated he was interested in having a cameo appearance in the films. At the end of the month, Dan T. Cathy, co-owner of Pinewood Atlanta, noted the films were "the largest film production ever with a $1 billion budget."

In March 2017, Terry Notary revealed he would appear in Infinity War as Thanos' right-hand man. Also that month, in terms of the Guardians of the Galaxy's roles in the films, Gunn stated despite them being mainly Avengers films, the Guardians are "a part of Thanos' stories, so, they are in there, and they have, not the biggest, but, an integral part to that." At Wizard World Cleveland 2017, Anthony Mackie confirmed he would reprise his role as Sam Wilson / Falcon in the films.