Avengers: Doomsday's Final Writing Credits Confirmed, With Two Marvel Actors Reportedly Involved

With so many moving parts in the Marvel Cinematic Universe, it's perhaps inevitable that the movie scripts are always changing, too. That's especially true for the incoming team-up movie "Avengers: Doomsday," which features a dizzying array of superheroes alongside the return of Robert Downey Jr., not as Iron Man but as classic Marvel villain Doctor Doom. Directors Anthony and Joe Russo have confirmed the reports that the "Doomsday" script was still being written while they were filming, describing themselves as "improvisation-based, rehearsal-based directors."

Even after filming is complete, it takes a while to determine which writers meet the criteria for a writing credit, per the Writers Guild of America's credit system. The WGA recently confirmed the two writers who will be given the main "written by" credit for "Avengers: Doomsday." One is Stephen McFeely, an MCU mainstay who co-wrote "Captain America: The First Avenger," "Avengers: Infinity War" and "Endgame," and several other titles. The other is Michael Waldron, who wrote the script for "Doctor Strange in the Multiverse of Madness" and created the well-received Disney+ series "Loki."

With a movie production as big as "Doomsday," however, there's almost always a hidden team of writers and script doctors who are brought in to help fine-tune and troubleshoot the script, or who worked on previous versions of it. And with an improvisational approach to production, actors will often add their own contributions via ad-libbing. Now, rumor has it that two actors in "Avengers: Doomsday" contributed enough to get an extra credit.

X/Twitter user Crystal4KQual, who has proven to be a reliable source for Marvel scoops, shared this tidbit: "I recently learned through their production companies, Ryan [Reynolds] and Hugh [Jackman] may get some form of screen writing credits on '[Avengers:] Doomsday,' too."

This wouldn't be the first writing credit for Reynolds, who co-wrote "Deadpool 2" and "Deadpool & Wolverine" alongside Rhett Reese and Paul Wernick. Actors aren't typically given writing credits just for ad-libbing some of their lines (or Reynolds would have a lot more credits to his name). However, in 2022, the Writers Guild of America introduced a new "additional literary material" credit for people who provided writing services for a movie but would otherwise be uncredited. The credit doesn't come with any residuals and doesn't equate to authorship (a writer can get an ALM credit even if none of their contributions end up on screen), but it does allow writers to put the experience on their resume.

"The Fantastic Four: First Steps," for example, had seven writers credited for additional literary material, including "Doomsday" screenwriter Michael Waldron. Indeed, given its complex development history, "Avengers: Doomsday" may end up with a similar number of ALM credits, including the "Spider-Man: Brand New Day" writing team of Chris McKenna and Erik Sommers, who were reported to have worked on the script.

We'll find out if Reynolds and Jackman did manage to snag any writing credits when "Avengers: Doomsday" hits theaters on December 18, 2026.