A pivotal moment that decided the fate of many in Avengers: Endgame was improvised, according to the director of Doctor Strange and Doctor Strange in the Multiverse of Madness.Doctor Strange director Scott Derrickson released a previously unknown tidbit about a big Doctor Strange moment in Avengers: Endgame. The scene takes place during the climatic battle of the Avengers vs. Thanos' army, in which the Sorcerer Supreme holds up his index finger to Tony Stark.Related: VIDEO: Why Scarlet Witch May Be Doctor Strange in the Multiverse of Madness' Villain

That move affected the entire climax that plays out in the next few minutes of the film. It turns out that the moment was improvised, according to what Doctor Strange actor Benedict Cumberbatch told the director.

In the final battle, Iron Man approaches Doctor Strange asking if this is the one out of 14 million+ chances for the good guys to win against Thanos. However, Doctor Strange doesn't answer Tony, explaining that if he did tell him, what needs to happen will not happen.

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But just as it seems Thanos will triumph over the Avengers yet again, Doctor Strange makes a motion to Tony. As they lock eyes, Doctor Strange holds up his index finger, telling him this is the one chance to beat Thanos. That one gesture sets in motion a heroic sacrifice for Tony Stark, in which he steals the Infinity Stones from the gauntlet worn by Thanos, snaps his fingers, and turns Thanos and his army to dust although the effort costs his own life.

Directed by Joe and Anthony Russo, Avengers: Endgame stars Robert Downey Jr. as Iron Man, Chris Evans as Captain America, Mark Ruffalo as Bruce Banner, Chris Hemsworth as Thor, Scarlett Johansson as Black Widow, Jeremy Renner as Hawkeye, Brie Larson as Captain Marvel, Paul Rudd as Ant-Man, Don Cheadle as War Machine, Karen Gillan as Nebula, Danai Gurira as Okoye and Bradley Cooper as Rocket, with Gwyneth Paltrow Pepper Potts, Jon Favreau as Happy Hogan, Benedict Wong as Wong, Tessa Thompson as Valkyrie and Josh Brolin as Thanos.

Source: Twitter