Avengers: Doomsday theory suggests RDJ isn't playing Doom after all

Avengers Doomsday is still a few months away, but that hasn’t stopped fans from analysing every frame of the most recent trailers.

They have come to one conclusion in these trailers due to a tiny detail may would have missed: that the eyes behind Doom’s mask are not Robert Downey Jr’s, and the whole casting of him as Doctor Doom is a red herring.

Hype for Doomsday has been slowly climbing amongst fans after an initial backlash to the concept, particularly amidst the re-release of Avengers Endgame which will be released in theatres 25 September 2026.

The Endgame re-release will feature an extra four minutes of runtime with scenes many expect to set up Doomsday more directly, and fans have also noticed that they changed the colour grading of the movie and in the process addressed the most common criticism of Endgame.

Seven years spoilers for the most-watched movie ever made – but Endgame of course ends with RDJ’s Tony Stark biting the bullet and sacrificing himself to save the world.

This of course led to one incredibly common question when it was announced he would be back as the big bad of the next two Avengers movies: “Huh?” As confusing as it is, according to a bunch of MCU fans, it could simply be because Dr Doom isn’t going to actually be played by RDJ, but will instead be a red herring, setting up Dr Strange actor Benedict Cumberbatch and another villain to be the big bads.

Fan theories suggest Doctor Doom isn’t played by Robert Downey Jr because of his eyes, but this could signal Doctor Strange is behind the mask

Doesn't look like RDJ to me... (Marvel)

This fan theory is pretty wild if it turns out to be true, but amongst all the debate of who is behind Doctor Doom’s mask one of the suggestions was that it could be Doctor Strange.

Benedict Cumberbatch has been surprisingly absent from marketing for the film, with Dr Strange: Multiverse of Madness leaving his character on a shocking cliffhanger where he grows a third eye in his forehead foreshadowing a villainous turn.

Some have speculated that Doctor Doom isn’t RDJ because the eyes behind the mask shown in the latest trailer were blueish green, not RDJ’s brown, which would fit with Doctor Strange’s actor Benedict Cumberbatch. In addition to this, RDJ’s face is never shown in the Doomsday trailers.

Others however have suggested that Doctor Doom could instead be played by a different actor altogether and that Doctor Strange could have a very different role inspired by the comics.

The comic for Secret Wars, which will be the sequel to Doomsday, features Strange in a very prominent role

Cumberbatch already played an evil version of himself in Multiverse of Madness (Marvel)

Secret Wars in the comic sees Doctor Doom reform the entire universe into something called ‘Battleworld’, and the ‘Sheriff of Battleworld’ was Strange.

This theory, originating on Reddit, suggests that RDJ’s Doom will be short lived, being killed off in Doomsday by the real Doom played by an as-yet unannounced actor.

Strange meanwhile will be one of Doom’s ‘followers’. These masked characters were first shown at D23 with leaked pictures showing a closer look at them. Of these masked mystery characters one has an eye hole around their forehead, which would of course now set up Doctor Strange as the most logical option.

One fan on Reddit said: “My theory is that when Avengers Doomsday starts or when we see 616 Dr. Strange he will be aligned with Dr Doom. Remember at the end of Multiverse of Madness, he was already going to stop an incursion.

“What if during this time he realizes how many more are occurring and somehow meets Doom. Instead of them fighting, Doom reveals his plan and ‘in the grand scheme of things’ their sacrifice is worth it? Remember Dr Strange is morally flexible to an extent.”

If your head is beginning to hurt and you think Doctor Doom just being played by RDJ to get butts in seats makes the most sense you can totally believe that, but if you think RDJ is terrible casting this theory makes perfect sense that Doctor Doom would be played by a different actor and amongst the big bad villains is Cumberbatch as some sort of second in command to a more powerful Doom.

Avengers Doomsday is available to watch 18 December, 2026.