10 MCU Films Fans Must Watch Before Avengers: Doomsday
As Avengers: Doomsday races toward its December 18, 2026 release date, hype for Marvel Studios’ biggest crossover event since Avengers: Endgame is reaching unprecedented levels. The return of directors Joe and Anthony Russo, the long-anticipated comeback of Robert Downey Jr. (in a shocking twist—as Doctor Doom, not Tony Stark), and the inclusion of Fox’s beloved X-Men cast have created a perfect storm of fan anticipation. The Multiverse Saga has been Marvel’s most ambitious narrative experiment, weaving together story threads from over a decade of films, shows, alternate universes, and corporate acquisitions. But with so much content, many fans are asking the same question:
What do I really need to watch before Doomsday?
While the Multiverse Saga spans dozens of projects, only a select number of films provide the essential groundwork needed to fully appreciate the stakes, character dynamics, and universe-breaking consequences coming in Avengers: Doomsday. Below is the definitive list of 10 MCU movies you must watch (or rewatch) before entering the next large-scale Marvel event. From the introduction of multiversal rules to the setup of Doom’s origins, these films form the backbone of the upcoming crossover.
Avengers: Endgame – The Foundation of the Multiverse Saga
Though Endgame concluded the Infinity Saga, it also quietly laid the groundwork for the Multiverse Saga’s biggest problems. Marvel Studios has since confirmed that the Avengers’ time-heist—originally a solution to Thanos’ cataclysm—created multiple unstable branches that would eventually grow into multiversal fractures. Endgame is, in many ways, the root of every problem the MCU now faces.
Why it’s essential
- Shows how branching timelines are created
- Establishes the emotional weight behind Tony Stark’s sacrifice
- Introduces alternate-timeline living (Steve Rogers’ ending)
It’s impossible to fully appreciate the stakes of Doomsday without revisiting how time travel and timeline splintering began. Steve Rogers’ decision to stay with Peggy, for instance, may not have been just a sweet epilogue—it could have long-term consequences, especially if the multiverse collapses.
Key elements to revisit
- The creation of new timelines during the time-heist, which become a major catalyst for multiversal chaos.
- Tony Stark’s death, whose impact echoes into the Multiverse Saga. Robert Downey Jr.’s return as Doctor Doom is rumored to parallel Tony’s legacy in haunting ways.
- Loki’s escape with the Tesseract, leading directly into the TVA, the collapse of timelines, and eventually the events preceding Doomsday.
If Avengers: Endgame was the closing chapter of one grand narrative, it also served—quietly—as the first chapter of another.
Shang-Chi and the Legend of the Ten Rings – Introducing the Rings’ Cosmic Mystery
Though initially perceived as a standalone origin story, Shang-Chi is now recognized as a crucial pillar of the Multiverse Saga. The mysterious Ten Rings are confirmed to emit a cosmic signal tied to unknown forces outside the timeline, and the film’s closing moments tie directly into the core conflict that Doomsday will explore.
Why it’s essential
- Establishes one of the MCU’s most important cosmic artifacts
- Introduces Shang-Chi, confirmed to appear in Doomsday
- Presents a mysterious beacon likely connected to Doom or a higher multiversal entity
Shang-Chi is positioned to be a major player moving forward—possibly one of the few heroes capable of resisting Doom’s multiversal manipulations.
Important connections
- The Ten Rings’ signal: a beacon of unknown origin, possibly from another universe.
- The Rings’ alien technology: suggesting ties to the multiverse or Doom’s advanced science.
- Continuity with canceled projects: Destin Daniel Cretton was once set to direct Avengers: The Kang Dynasty, hinting that Shang-Chi’s mythology was always meant to intersect with the Saga’s main antagonistic forces.
Shang-Chi’s powers, origins, and artifacts are far more connected to the MCU’s future than they initially appeared.
Spider-Man: No Way Home – The Multiverse in Full Force
No Way Home remains one of the MCU’s most important multiverse experiments—both narratively and culturally. Not only did it prove the viability of cross-franchise storytelling, but it also set the template for incorporating legacy characters into the MCU.
Why it’s essential
- Demonstrates how variants cross into Earth-616
- Lays out early rules for multiverse instability
- Reintroduces Tobey Maguire and Andrew Garfield’s Spider-Men
Every indication suggests that both legacy Spider-Men may return for Doomsday, especially with the multiverse collapsing and Earth-10005 converging with Earth-616.
Key reasons to rewatch
- Doctor Strange’s spell, which destabilizes the multiverse in ways still unfolding.
- The concept of “pulling” characters across universes based on identity and memory.
- The emotional consequences of being forgotten, which continues in Peter’s story leading into Spider-Man: Brand New Day.
No Way Home is where the MCU truly embraced the multiverse—and it's essential to understanding what comes next.
Doctor Strange in the Multiverse of Madness – Multiversal Rules & Incursion Setup
If No Way Home opened the multiverse’s doors, Multiverse of Madness examined the rules, consequences, and cosmic dangers of leaving them open. The film’s introduction of incursions—the violent collision of universes—casts a long shadow over the Multiverse Saga.
Why it’s essential
- Introduces incursions, the saga’s biggest threat
- Brings America Chavez into the MCU
- Highlights Earth-616’s growing instability
With America Chavez almost certainly returning for Doomsday, understanding her powers—and her role as a Nexus Being—is crucial.
What it contributes
- The Illuminati of Earth-838, foreshadowing that universe’s importance in upcoming films.
- Wanda’s world-breaking power, hinting that cosmic-level beings will play a significant part in the multiverse crisis.
- Clear definitions of incursions, which Doctor Strange warns are inevitable and destructive.
This film provides the vocabulary of the Multiverse Saga—without it, Doomsday’s stakes will feel incomplete.
The Marvels – The Gateway to Fox’s X-Men Universe
Though divisive among fans, The Marvels contains arguably the most important post-credits scene in the Multiverse Saga so far. Monica Rambeau’s fate is the clearest direct pipeline into the Fox X-Men universe (Earth-10005).
Why it’s essential
- Directly connects Earth-616 to Earth-10005
- Positions Photon as a key multiversal hero
- Sets the stage for the X-Men’s MCU arrival
Critical details
- Monica trapped in the Fox X-Men universe, a monumental crossover moment.
- Beast’s appearance, confirming Earth-10005 as part of the MCU’s larger multiverse.
- Photon’s future role, likely involving the rescue of heroes stranded across universes.
The Marvels is the bridge between eras—between the MCU and one of the most iconic superhero franchises in film history.
Deadpool & Wolverine – The Most Important Multiverse Movie Yet
Perhaps more than any other film on this list, Deadpool & Wolverine is required viewing before Doomsday. The movie dives headfirst into TVA operations, the Void, collapsing timelines, and new metaphysical concepts like Anchor Beings.
Why it’s essential
- Introduces Anchor Beings
- Expands TVA lore and multiversal collapse
- Connects directly to Earth-10005
- Reintroduces Fox characters who appear in Doomsday
It’s the MCU’s most multiverse-heavy project yet and is reported to tie directly into the events of Doomsday.
Key ideas
- The Void and timeline pruning, which will be critical when universes start colliding.
- The role of Anchor Beings, individuals whose removal destroys timelines—a concept rumored to be central to Doom’s plan.
- Cameos from Fox’s Marvel characters, including those who will return in Doomsday.
The film also deepens the emotional and narrative stakes around universes collapsing—a theme that will dominate the next Avengers film.
Captain America: Brave New World – Rebuilding the Avengers
As the MCU transitions into its next era, Brave New World repositions Sam Wilson as the new leader of an uncertain and fractured Avengers team.
Why it’s essential
- Shows the global state post-Endgame
- Positions Sam Wilson as Earth-616’s primary Avengers leader
- Introduces Adamantium into the MCU
What to focus on
- Sam’s hesitant leadership, contrasting sharply with Tony and Steve’s approach.
- International political instability, which will affect how nations respond to multiversal threats.
- The emergence of Adamantium, potentially tying into Doctor Doom, Wolverine, or future X-Men arcs.
Brave New World sets the tone for Earth-616’s leadership crisis heading into Doomsday.
Thunderbolts – The Birth of the New Avengers
Serving almost as an Avengers film in disguise, Thunderbolts introduces the New Avengers—a team that will clash ideologically with Sam Wilson’s Avengers in Doomsday.
Why it’s essential
- Establishes the New Avengers lineup
- Features the Watchtower, formerly Avengers Tower
- Ends with a post-credits scene directly tied to Doomsday
Key takeaways
- The Thunderbolts roster: Yelena Belova, Winter Soldier, Red Guardian, Ghost, U.S. Agent, and Sentry.
- The Watchtower, the team’s new headquarters located in the old Avengers Tower.
- A Fantastic Four tease, with their ship appearing through a dimensional rift in the post-credits scene.
This film sets up political tension, team rivalries, and cosmic events that will collide catastrophically in Doomsday.
The Fantastic Four: First Steps – Doctor Doom’s True Debut
This film is the most direct lead-in to Avengers: Doomsday. Not only does it feature the first full appearance of Robert Downey Jr. as Doctor Doom, but it takes place on Earth-838, a universe already destabilized by Scarlet Witch.
Why it’s essential
- Introduces Doom in his new MCU incarnation
- Showcases Earth-838’s fractured state
- Establishes Franklin Richards as a major figure
Important elements
- Earth-838’s importance, confirmed through Doom, Reed Richards, and the Illuminati’s legacy.
- Franklin Richards, whose reality-altering powers make him a major target for Doom.
- The mid-credits confrontation, which sets Doom’s sinister plans in motion.
This is the film most directly tied to the upcoming Avengers event—and missing it would leave a major gap in understanding Doom’s motivations.
Spider-Man: Brand New Day – The Final Stop Before Doomsday
Set to release mere months before Avengers: Doomsday, Spider-Man: Brand New Day will almost certainly serve as the final narrative bridge. While details remain under wraps, early reports strongly suggest that the film’s post-credits scene will lead directly into Doomsday.
Why it’s essential
- Continues Peter Parker’s story after No Way Home
- Likely introduces important final pieces of the multiverse puzzle
- May feature Doctor Doom (rumored but unconfirmed)
What to expect
- The emotional fallout from Peter’s isolation after Strange’s spell.
- A potential connection to the Fantastic Four or Earth-838, tying Peter’s scientific background into larger cosmic events.
- A post-credits scene intended to tee up the opening act of Doomsday.
Brand New Day is expected to be the final puzzle piece before the multiverse shatters.
Final Thoughts
With Avengers: Doomsday shaping up to be the MCU’s most ambitious movie ever, these ten films form the essential narrative roadmap to fully understand the brewing crisis. The Multiverse Saga is about more than timeline fractures—it’s about the legacy of past heroes, the consequences of universe-altering choices, and the rise of a villain whose power equals (or exceeds) any we’ve seen before.
Whether through the cosmic mystery of the Ten Rings, the multiversal rules laid down in Multiverse of Madness, or the emotional weight carried forward from Endgame, each movie on this list contributes a vital piece to the Multiverse Saga’s final confrontation.
Revisiting them now will ensure you’re fully prepared—for the return of the X-Men, the arrival of the Fantastic Four, the rise of Doctor Doom, and the most explosive crossover event Marvel Studios has ever attempted.
The multiverse is collapsing. And everything we’ve watched has been leading to this.
