Directors Joe and Anthony Russo have confirmed what we've all known. Avengers: Endgame wasn't the original title of Marvel's 22nd film. It was Avengers: Infinity Gauntlet.
In an appearance on the HappySadConfused podcast, the sibling director duo said that "Well, it was Infinity Gauntlet for a long time." In 2017, actor Zoe Saldana had let slip in an interview that the cast was shooting 'Gauntlet', which led many to believe that the fourth Avengers film would be titled Infinity Gauntlet. Marvel was quick to deny this.
After previously refuting reports that the film's title had been spoken in Avengers: Infinity War, it was revealed at the end of the first teaser trailer in November. The biggest indicator that Endgame would be the eventual title of the film came when cinematographer Trent Opaloch put it up on his website.
Anthony Russo explained why calling the film Endgame created a bit of a problem that they hadn't anticipated. "When we went to Korea to promote this movie, the representatives from Disney there came up to us and said, 'Um, there's something we need to tell you. In the translation of Infinity War here in Korea, when Doctor Strange says to Tony, 'We're in the endgame now,' the way we translated that here was 'no hope.' So we're like, 'Oh, so I guess in Korea, is this movie called 'Avengers: No Hope?'"
Avengers: Endgame is now the second highest grossing film of all time, trailing James Cameron's Avatar by approximately $500 million.