Robert Downey the only Avenger the Russos trusted with Endgame script

Well, maybe Chris Evans, because Captain America can keep a secret.

Iron Man can be trusted.

Avengers: Endgame directors Joe and Anthony Russo, have been asking fans who see the film to keep its secrets and not spoil it for others. But they also had to protect the film's secrets from its own stars, even if that means not giving them full copies of the script.

"(Robert Downey Jr.) was probably the only one to read the entire script," Joe Russo said in an interview with Rotten Tomatoes, though he later allowed that Chris Evans (Captain America) might also have read the whole script.

Some other actors, including Benedict Cumberbatch, who plays Doctor Strange, got a copy that included his scenes only, Joe Russo said.

"Part of our motivation to do that is it just takes a lot of pressure off of people, because it is hard to constantly censor yourself," Anthony Russo said. "So we take a lot of pressure off of people by just saying, 'OK, the less you know, the less you have to mind yourself."

Joe Russo noted that the directors handled Avengers: Infinity War in a similar way, giving, for example, Chris Hemsworth, who plays Thor, only his scenes.

"There's more secrets in Endgame than there are in Infinity War," he said.

The brothers also teased that there could be fake footage in the Avengers: Endgame trailers.

"Maybe it's all fake," said Anthony Russo with a laugh. "Maybe there's not a real frame in that whole trailer."

Fake trailers or real, Avengers: Endgame opens April 26 release in the US, April 25 in the UK, and April 24 in Australia.