Small coincidences and character choices have major impacts on the MCU timeline. Even trivial moments like phone calls and getting fired have huge impacts in the MCU. Small moments often end up having huge impacts on MCU character arcs as well, playing major roles in the stories of figures like Doctor Strange and Iron Man.

Throughout the MCU, while major battles, deaths, and character introductions have shaped the trajectory of individual stories and larger arcs, smaller coincidences and character choices have also had substantial impacts on the MCU timeline. Some of the most significant, defining moments throughout the franchise stemmed from a seemingly inconsequential event forever reshaping the MCU. In fact, shows like What If…? suggest just how monumental these small changes can be, throwing into sharp relief that the minor details throughout Marvel’s films and TV shows are not only critical, but also worth paying attention to.

Because the MCU has so consistently implemented ensembles into their content, particularly in the films, the variables impacting the events in the MCU are innumerable and can often lead to a sort of butterfly effect. In every Avengers movie, for example, each character has the potential to create ripple effects that will change not only the outcome of that film’s story but also the future of the larger MCU, for better or worse. This makes even the most seemingly trivial moments vital, and these 10 events, some comically small, demonstrate just how major those tiny shifts can really be.


Every Upcoming Marvel Movie: Full MCU Phase 5 & 6 List (& Beyond)

Between Marvel Studios and Sony Pictures Entertainment, here is every upcoming Marvel movie release date and what we know about the projects so far.

10 A Rat Stepping On A Button Helped Defeat Thanos

Avengers: Endgame (2019)

In Avengers: Endgame, Scott Lang – who has been stuck in the MCU’s Quantum Realm since the events of Ant-Man and the Wasp (2018) – only returns because a rat inside Luis’ van, which contains the Quantum Realm connection Scott uses, steps on a button, finally bringing Scott back after being trapped for five years. This one little rat sets in motion the events of Avengers: Endgameand allows the Avengers to identify a path forward: time travel. With the insights Scott has from his time in the Quantum Realm, along with significant scientific help from Tony Stark, the team establishes a plan to collect the Infinity Stones, undo the Snap, and defeat Thanos.

9 One Phone Call Made Doctor Strange

Doctor Strange (2016)

In Doctor Strange, Stephen Strange’s life is changed forever when he accepts a phone call while driving, contributing to the crash that ultimately severely damages his hands and effectively ruins his career as a surgeon. In the wake of the crash, Dr. Strange becomes desperate to undo his injuries and restore his career, which leads to him finding the Sorcerer Supreme and developing his powers, thereby creating Dr. Strange of the Avengers. Without that crash, Dr. Strange would have remained an egotistical surgeon and would not have become the powerful superhero who saves the world countless times, though perhaps most notably in Avengers: Infinity War and Avengers: Endgame.

8 Yondu Keeps Quill With The Ravagers

Guardians of the Galaxy (2014)

When Yondu is hired by the god Ego to kidnap his son, young Peter Quill, from Earth, he does, but he cannot see the rest of the plan through. Rather than bring Peter to Ego, Yondu raises Peter, albeit with some questionable methods. What If…? season 2 addressed what a massive impact this had; in the second episode, titled “What If… Peter Quill Attacked Earth’s Mightiest Heroes,” Peter is brought to Ego by Yondu, and he becomes a weapon for his father. This glimpse into what could have been shows how significant Yondu’s choice was; he gave the MCU a hero when it could have had another major threat.

7 The Hulk Is Forced to Take the Stairs

The Avengers (2012)

In The Avengers (2012), The Hulk is forced by the Avengers to take the stairs, which sends him into a rage. This seems like just an inconsequential comedic moment, but this small detail leads to Loki becoming The God of Stories in the Loki series. In Avengers: Endgame, Tony Stark, Ant-Man, and Captain America revisit this moment in time to collect the Tesseract, which contains the Space Stone. When Hulk emerges from the staircase, he bursts through the door, knocking over Tony Stark from the future in the process. This sends the briefcase containing the Tesseract flying out of Tony’s hand, and the Tesseract lands at Loki’s feet.

When Loki leans down, grabs the Tesseract, and uses it to disappear, he becomes a variant. This is precisely why the MCU’s Time Variance Authority (TVA) comes after him, triggering the events of the Loki series. While this would be a significant impact enough, the reach of this moment extends far beyond just the show. By the series finale at the end of Loki season 2, Loki has taken the place of He Who Remains, becoming the being who holds together the Sacred Timeline. As such, had Hulk not been required to take the stairs (and been angry about it), Loki would not be The God of Stories.

6 Carol Danvers Won the Race to the Hangar

Captain Marvel (2019)

In Captain Marvel, Carol Danvers is in the Air Force before she becomes a superhero, working under Dr. Wendy Lawson, a.k.a. Mar-Vell. She and her best friend, Maria Rambeau, race one another to meet Dr. Lawson at the Air Force hangar, which ultimately changes Carol’s fate and the fate of the MCU. Because Carol beats Maria to the hangar, she is the one who joins Dr. Lawson, which leads to Carol being present when Dr. Lawson is killed, absorbing the power of the Space Stone, and becoming Captain Marvel. Doctor Strange in the Multiverse of Madness seems to nod to this by having Maria Rambeau as Captain Marvel on Earth-838, suggesting she won the race instead in the alternate timeline.

5 Kamala Opens a Box from her Nani

Ms. Marvel (2022)

In Ms. Marvel, Kamala Khan discovers her powers by slipping on a bangle that turns out to be a Quantum Band, but she only finds the object by opening a package from her grandmother. By making the bracelet a part of her costume that she is wearing to a superhero convention, she inadvertently kick-starts her powers, ultimately becoming Ms. Marvel. Had her Nani not sent her the bracelet, or had Kamala not kept it and tried it on, Kamala would not have unlocked her powers. With The Marvels’ mid-credits scene confirming the first three Young Avengers members, this moment will become even more significant as the MCU goes on.

4 Thanos Spots Young Gamora

Avengers: Infinity War (2018)

When Thanos and his army arrive on Zen-Whoberi to execute half the population, young Gamora and her mother hide, only to be discovered and pulled apart. It’s then that Gamora begins yelling and attacking some of Thanos’ army, which catches Thanos’ attention. This small moment, where Thanos saw Gamora among the chaotic masses, changed the MCU irrevocably. Because Thanos saw something special in Gamora, he took her in as a daughter, making her into a deadly assassin. In addition to this, though, Gamora becomes the one person that Thanos loves, allowing him to kill her and get the Soul Stone.

With the Soul Stone, Thanos is ultimately able to complete his Infinity Gauntlet and carry out the Snap, eliminating trillions. It’s unclear whether Thanos had anyone else he loved who would have enabled him to get the Soul Stone on Vormir; it doesn’t seem those sentiments carried over to other Children of Thanos, particularly Nebula. Meeting Gamora may therefore have been key to his plan; had Thanos’ life contained no loved ones, his plan would have halted there. This means that not only does the moment Thanos meets Gamora have implications for The Guardians of the Galaxy, but also that Thanos seeing her at this moment cements the future Blip.

3 Scott Lang Gets Fired from Baskin-Robbins

Ant-Man (2015)

One of the funniest small MCU moments with a massive impact is Scott Lang getting fired from Baskin-Robbins in the first Ant-Man movie. Scott is trying to find work, in part because he’s behind on child support and can’t see his daughter, Cassie. When this brief stint at Baskin-Robbins doesn’t work out, he turns to a quicker way to get money: theft. This ultimately leads him to Hank Pym’s house, where his path to becoming Ant-Man begins. Given that, it’s fair to say that, had Scott never been fired from Baskin-Robbins, he may never have become Ant-Man. This would have had massive implications for Avengers: Endgame, as well.

2 Steve Rogers Was Too Short and Skinny for the Military

Captain America: The First Avenger (2011)

In Captain America: The First Avenger, Steve Rogers is desperate to join best friend Bucky Barnes and fight in the war, but he’s not big enough. At the beginning of the film, Steve is just 5’4″ and around 90 lbs. Because of that, he was seen as unfit to fight, sending him down the path of wanting to become a super soldier, which ultimately creates Captain America. Not only would the world never have had Captain America, but also the many events throughout the MCU that Captain America plays a major role in would have played out differently — all because Steve was at first too short and lightweight to sign up to fight.

1 Tony Stark Gets Hit with Shrapnel

Iron Man (2008)

In Iron Man, before Tony Stark has any powers, he visits a war zone in Afghanistan and is seriously injured and taken captive during an attack. Part of his injury involves shrapnel, which threatens to get to his heart and kill him. To prevent that, Tony creates the arc reactor that not only protects against the shrapnel but also offers a massive power source for his Iron Man suits. This initial incident sets in motion the path to Tony Stark becoming Iron Man. Given how critical Iron Man is to the Avengers team, especially during Avengers: Infinity War and Avengers: Endgame, this bit of shrapnel represents a massive shift in the MCU.

Key Release Dates

Deadpool 3

Captain America: Brave New World

Marvel’s Fantastic Four

Marvel’s Thunderbolts

Blade (2025)

Avengers: The Kang Dynasty

Avengers: Secret Wars

 10 small MCU moments caused major changes.  Read More