Through three phases of the Marvel Cinematic Universe - consisting of nearly two dozen films and hundreds of hours of additional content - there has been no shortage of onscreen displays of heroism. That’s to be expected from a mega-franchise centered on the exploits of super-characters, but there are still some moments that stand out even among the ranks of Earth’s Mightiest Heroes. And nothing says “hero” like putting one’s own life on the line to protect the lives of others. (Of course, the MCU has seen a handful of dumb heroic sacrifices, as well.)
The protagonists of the MCU come in a wide variety of shapes and sizes - Avengers, Guardians of the Galaxy, and Agents of S.H.I.E.L.D. included - but they’re all united by the heroic trait of selflessness. Time and time again, the heroes of Marvel Studios have risked, and even sacrificed, themselves whenever necessary - which turns out to be pretty frequent in a universe filled with alien armies, malevolent deities, and evil planets. That’s always been the Endgame to being a hero in the Marvel Cinematic Universe.
When: Avengers: Endgame (2019)
Steve Rogers once opined that Tony Stark wasn’t one to make the “sacrifice play,” and Iron Man has spent the rest of his cinematic career proving that wrong. The culmination of Stark’s heroic arc is also the sacrifice that saves the entire Marvel Cinematic Universe from destruction at the hands of Thanos.
When he comes up with the idea to take the Infinity Stones via nano-thievery and then snap Thanos’s forces out of existence, he knows full well that it will end him. All it takes, however, is a quick glance at Doctor Strange to confirm his plan will work - and one last “I am Iron Man” - for Stark to act.
When: Avengers: Endgame (2019)
Many of the sacrifices in the Marvel Cinematic Universe are undertaken to save the lives of countless others, but the sacrifice that Natasha Romanoff makes on Vormir is much more personal. Both she and Clint Barton know that one of them must perish in order to successfully retrieve the Soul Stone - and neither of them wants to let the other sacrifice themselves.
In the end, the Black Widow wins the grim contest and hurls herself off a cliff - while simultaneously bolting Hawkeye to the cliffside - giving her life so that the Infinity Stones can be reunited and half the universe can be restored to life. She does so knowing that such a sacrifice will be permanent and that not even the Infinity Stones themselves can return her to life - and she still does it without hesitation.
When: Guardians of the Galaxy Vol. 2 (2017)
Yondu Udonta is more of an antagonist than anything in the first Guardians of the Galaxy adventure, but he makes a rather quick face-turn by the time the sequel is complete. Revealed as a surrogate father-figure to Peter Quill, Yondu solidifies himself as Star-Lord’s “daddy” by sacrificing his life to rocket Quill off a collapsing planet - a planet that happens to be Quill’s biological father.
Unlike some of the other notable sacrifices of the MCU, this one is planned out in advance - Yondu knows that he only has one jetpack and one spacesuit, so only one of he and Peter can safely escape Ego’s atmosphere. Yondu willingly gives his life to save that of his son, but not before taking the opportunity to finally speak of his paternal pride.
When: Guardians of the Galaxy (2014)
Long before any of the Avengers gave their lives, one of the Guardians of the Galaxy sacrificed themselves to save their teammates - the original Groot. While a younger version of Groot is still traveling around the universe with Rocket Raccoon, it’s a clone-child of the genuine article - and OG Groot’s sacrifice is very much a legitimate one.
With the Guardians trapped on the Dark Aster as it's going down, Groot extends his body into a wooden sphere that encompasses his teammates - shielding them from the impending collision with Xandar. The force of the impact completely wipes out Groot’s wooden frame, but his message of “We Are Groot” informs the Guardians’ next act of selflessness shortly thereafter.