This became the biggest pre-sale title ever on Fandango and Atom Tickets sites, causing them to crash minutes after the sales were announced. It accomplished this feat in only six hours. Some theaters across the world had so many sold out showtimes on the opening weekend that Cinemark, Regal, and AMC theaters chose to add new overnight screenings so they'd be working around the clock to accommodate extra shows.
This film and its predecessor Avengers: Infinity War (2018) were filmed entirely on digital IMAX cameras, making them the first Hollywood films shot entirely on IMAX cameras in an exclusive open-matte aspect ratio of 1.9:1.
As they did with the previous film, the Russo Brothers wrote a letter to fans, asking them not to spoil anything about the movie, as part of a viral campaign on the internet. The hashtags were #DontSpoilTheEndgame and #ThanosDemandsYourSilence.
The first trailer was posted by Marvel Entertainment simply as "Marvel Studios' Avengers - Official Trailer", without the film's title in the name of the video, in order to surprise the fans with the title's reveal at the end of the trailer.
In September 2018, the Russo Brothers posted a picture on social media of the film's set, with the caption "Look Hard". This lead many to speculate and believe the title of this film was hidden somewhere inside the photo.
The North American release date was moved up a week earlier from May 3rd to April 26th, 2019, after the first trailer and title released on December 7th, 2018. There was much speculation that Marvel Studios would do this, as they moved "Infinity War's" release up a week as well, in order to reduce the possibility of major plot leaks from countries that released the film earlier.
When the Russo Brothers tweeted out a photo of the re shoot cast. Yvette Nicole Brown from Community was in that photo. Making her the fourth cast member from Community to appear in a Russo Bros. MCU film.
During an event of Guardians of the Galaxy Vol. 2 (2017) in April 2017, Zoe Saldana revealed the title of the film as Avengers: Infinity Gauntlet. Following this, James Gunn announced that was not the title.
The first poster released featured Okoye but did not include Danai Gurira's name among the rest of the cast members' names at the top of the poster. That poster was quickly recalled and replaced with one that did include her name.
Brie Larson (Captain Marvel) and Chris Evans (Captain America/Steve Rogers) have previously starred in Scott Pilgrim vs. the World (2010) together before either of their appearances in the Marvel Cinematic Universe. Larson played the rock star Envy Adams (Scott's (Michael Cera) ex-girlfriend), and Evans played the action movie star Lucas Lee (one of Ramona's (Mary Elizabeth Winstead) Seven Evil Exes). In addition, that movie was directed and co-written by Edgar Wright, who wrote the original screenplay for Ant-Man (2015) (a character who also appears in this movie) but dropped out as director for that movie due to his creative clashes with Marvel Studios.
It is the 3rd Avengers movie to be released in the same year as a Quentin Tarantino movie. The Avengers and Django Unchained were both released in 2012, Avengers: Age of Ultron and The Hateful Eight were both released in 2015 and Avengers: Endgame and Once Upon a Time in Hollywood are both being released in 2019.
Steve Rogers ends up in an aged form by the end of the film and hands the shield and the Captain America title over to Sam Wilson. This came from the comics, when Steve Rogers was temporarily turned into an old man by having the Super-Soldier serum drained from his body forcing Sam to become Captain America during the 2014 comic book storyline "The Tomorrow Soldier". For this film, while he has the serum, it didn't stop the aging. So when he takes the long way back to the present after one-way time-travelling to the 40s, it shows.
Endgame was Robert Downey Jr.'s last contractual obligation to play Tony Stark/Iron Man for Marvel Studios. Downey has stated he plans on being involved with the Marvel Cinematic Universe longer than his current contractual commitments are structured, so many are led to believe he will sign a new deal after his current one has concluded.
Steve Rogers dupes the Hydra agents into believing he's an undercover Hydra agent himself. This came from the "Secret Empire" comic storyline, where Rogers was revealed to have been a member of Hydra (it was revealed to have been a clone created by Hydra).
Set photos leaked showing Robert Downey Jr., Chris Evans, Chris Hemsworth and Tom Hiddleston wearing outfits and costumes from the first Avengers film, as well as the rubble-filled New York set during which the final battle of The Avengers (2012) is set. This leads many to believe that either a flashback sequence or time travel will play a major role in this film. The fact that Ant-Man is seen among these characters creates the speculation that he will be the one to travel back in time by means of the Quantum Realm; this theory seems all the more likely after the mid-credits scene of Ant-Man and the Wasp (2018) where he becomes trapped in the Quantum Realm after receiving the warning to avoid the time vortex.
Clint Barton appears in Japan with the identity of Ronin in this film. This is based on the comics, where in the aftermath of the Infinity War event he took up the Ronin identity during a mission to Japan. Barton has a tattoo of a ronin on his arm, as a further homage.
With this film along with Captain America: Civil War, Spider-Man Homecoming and Avengers Infinity War, Tom Holland breaks Tobey Maguire's record for playing Spider-Man in live action movies the most times.
During the end credits, when the main cast names are shown. Their names are also shown alongside their signatures, along with a picture of their character. This is very similar to the end credits to Star Trek VI: The Undiscovered Country. Where the actors signatures appear on screen, that film was also a final outing for the original crew, much like Avengers: Endgame.
Aaron Taylor-Johnson's character, Quicksilver, was seen on set pics of this film. Hinting that he might return or will just briefly make an appearance in a flashback scene of Avengers: Age of Ultron (2015). In the final cut of the movie, he is missing.
Captain America wields Thor's Mjolnir hammer against Thanos. This came from the comics, where Steve Rogers has repeatedly wielded Mjolnir in battle, proving himself worthy by the enchantment cast on the hammer. This also marks the second film where Steve Rogers makes an attempt to wield Mjolnir, the first was in Avengers: Age of Ultron (2015), though unlike the previous film he wielded the hammer openly (whereas in Age of Ultrton he moved the hammer and set it back down)
For the first time in the MCU since The Incredible Hulk in 2008, there is no mid or post credit scene. The final Marvel logo, however, is paired with a characteristic sound from the very first movie one of the characters dying in this movie appeared in.
The downer ending to Avengers: Infinity War was going to be this film's beginning; had that been the case, Infinity War would have ended with Thanos completing the Infinity Gauntlet before actually using it in this movie. However, the creative teams working on the two films decided that it best suited the story to have the actual cliffhanger follow the fingersnap itself and to show its fallout before, making viewers wait a year to see how the story would be resolved.
Edwin Jarvis, played by James D'Arcy, becomes the first character in the MCU to be introduced in a Marvel's TV series and make an appearance in a movie. The character was first introduced in Agent Carter: Now Is Not the End (2015). This also marks the first time the original Jarvis is seen in a film, as he had been replaced by the computer program J.A.R.V.I.S. in previous films.
"New Asgard", is actually a village in the southern borders region of Scotland, called St Abbs. Thor can be seen drinking Innes and Gunn, a beer brewed in Scotland. Other hints to Scotland in this scene are the bottle of Irn Bru on the windowsill, and the golf club behind Thor's head.
Rumored to be titled Avengers: End Game, after a comment made by Doctor Strange in Avengers: Infinity War (2018). This was also more believed after a fan looked at one of the cinematographers' credits, where it listed the title Avengers: End Game in the films he has/or will do. This was later confirmed to be the case.
Toward the end of the second official trailer, the Avengers are all wearing identical white suits as they stride off to supposedly save the day. These suits bear somewhat a resemblance to the Quantum suit worn by Hank Pym in Ant-Man and the Wasp (2018), which further adds on to the theory that the Avengers will use the Quantum Realm to reverse Thanos' actions in the previous movie. Tom Holland had already spoiled by accident in an interview that the Quantum Realm will play a major role in this movie.
This movie's storyline is the ultimate payoff to Tony Stark's statement in The Avengers (2012) where he tells Loki "If we can't protect the Earth then you can be damn well sure we'll avenge it". In Avengers: Infinity War (2018), they failed to save the universe, which is why they'll be avenging it in this movie.
Steve Rogers' line "Hail Hydra" is a reference to the 2016 comic book Captain America: Steve Rogers #1. The comic book ended in a massive cliffhanger with Steve Rogers apparently revealing his allegiance to Hydra, which caused an outrage among fans.
It is rumored that Bruce Banner and the Hulk will merge into one identity that dubs itself the Professor. This is based on the Merged Hulk (Banner and Hulk merged into one body), and is named after the Maestro (another merged form - "maestro" is Italian for "Professor"; however the Maestro was a villain in the comics, while the Professor is still heroic).
Despite rampant rumors that it may happen due to Fox being acquired by Disney, no non-MCU characters appear in the film (X-Men, Deadpool, Fantastic Four, etc.) There is also no indication as to how these characters may be incorporated in the future.