If you found Avengers Endgame’s time travel a bit of a head-scratcher you weren’t the only one. The Marvel epic went out of its way to be closer to the real-life theory of travelling to the past, rather than the sci-fi tropes we’re used to in movies like Back to the Future. However, it now turns out the time travel rules were changed during the reshoots. Related articles Avengers Endgame: Will the NEW Marvel TV shows be LINKED to the MCU? Avengers Endgame: Will Chris Hemsworth be ‘fat Thor’ in Guardians 3? Speaking with IndieWire, Ancient One star Swinton revealed that her reshoots added an important time travel explanation. On returning as her character, who died in Doctor Strange, for a scene in 2012 New York, she said: “It was a surprise to me, too! “And it was a pleasure. But what was a real surprise was, we shot it one summer day, and then over a year later, I went back to reshoot it because a couple of lines had been changed. “A couple of plot points had been changed and there was a tweaking of my costume.” Avengers Endgame star Tilda Swinton reveals reshoots CHANGED time travel rules (Image: MARVEL) Avengers Endgame's time travel was closer to the real-life theory than Back to the Future (Image: MARVEL) Asked to clarify what the big change was, she said it was adding in the “very, very important.” visual timeline. Specifically, this was when the Ancient One tells Bruce Banner that the Infinity Stones cannot leave their timeline due to being at risk of creating a worse alternate future. This is when Hulk points out that if the stones are returned to the exact moment in the timeline, it’s as if they never left. Swinton added that the new lines tied into emphasising how the time travel rules were not what sci-fi fans are used to in movies like Back to the Future. BACK TO THE FUTURE THE MUSICAL COMES TO THE UK IN 2020 Related articles Marvel movies: What will the next Marvel movies be? Avengers Endgame: Chris Hemsworth 'Fat Thor' making-of secret revealed The big difference is you can change the past in Back to the Future (Image: UP) Interestingly, Avengers Endgame screenwriters Christopher Markus and Stephen McFeely have disagreed on aspects of the time travel with directors The Russo Brothers. Specifically in relation to if at the end of the film, Cap created a new timeline where he went back in time to live with Peggy, or if he lived in the prime timeline all along and was her secret husband. Hopefully, the Disney+ series and some tie-in comics will help explain these currently mysterious moments in the MCU canon. Avengers Endgame is out now.All rights reserved for this news site express.co.uk and under his responsibility