How Captain America Became Worthy

The Two Best Fan Theories on Why Steve Rogers Could Wield Mjolnir in Avengers: Endgame

One of the most thrilling scenes in Avengers: Endgame occurs during the climactic battle against Thanos. As Thanos appears on the verge of killing Thor by forcing the ax/hammer Stormbreaker into his chest, he is suddenly struck from behind by Mjolnir, Thor's other weapon. Mjolnir arcs back and returns to the hand of a new wielder, Steve Rogers, Captain America.

This was an amazing moment because of the mystique of Mjolnir. The mighty hammer not only packs a massive punch, but always returns to the hand of its user, can generate wind enough to make the holder fly when spun quickly, and can unleash huge lightning bolts. Mjolnir can only be used or even lifted by someone considered worthy, by Asgardian standards, to control its massive powers.

Thor's original journey in his first movie followed the crushing loss of his powers when his father deemed him unworthy, and his maturing to regain them, along with Mjolnir. Since then, he was the only person able to use that weapon.

A key scene in Avengers: Age of Ultron shows all of the Avengers sitting around after a party, discussing Mjolnir. In an amusing montage, everyone takes a turn at attempting to lift it, and all fail. However, Steve Rogers is able to ever-so-slightly budge the hammer, bringing a concerned expression to Thor's face. However, when he shifts his grip and bears down, the hammer does not move any further, to Thor's obvious relief.

It was a nice moment on its face because it underlined that Steve Rogers is a noble and heroic character, a mere mortal who was very nearly worthy to lift a mystical Asgardian weapon. But fans wondered: what made the near-saintly Captain America unworthy? Was it simply because no mortal could harness a god's power, or was there some unseen blemish on Cap's character? Or was something else going on?

In the wake of the revelations of Captain America: Civil War, fans theorized that, at the time of that party, Steve already knew about Bucky/Winter Soldier's role in the murder of Tony Stark's parents. He did not tell Tony what he knew, and that revelation at the climax of Captain America: Civil War nearly destroyed their friendship permanently. In this theory, keeping that dangerous secret marred Steve enough that he could not lift Mjolnir, though he was so close to worthy that he could move it slightly.

With that secret out and off his conscience, everything that Steve subsequently sacrificed and accomplished through the events of Avengers: Infinity War and Avengers: Endgame polished off that last bit of unworthiness, preparing him to be able to wield the mighty Mjolnir at the crucial moment.

However, there is another, competing theory: Steve Rogers was always able to lift Mjolnir, and simply chose not to! 

This interpretation also makes sense, because, during that crucial scene in Age of Ultron, the audience (and Steve) could see that Thor was very nervous when it appeared that someone else could lift Mjolnir, and was visibly relieved when Steve could not do it after all.

As Captain America, Steve is one of the leaders of the Avengers, and a good leader knows when to give way to help the team as a whole. Undermining Thor's confidence would not have helped the team.

Also, at that time, everyone's understanding was that most of Thor's power emanated from Mjolnir, and the actual incantation that Odin placed on the hammer states, "Whosoever holds this hammer if he be worthy, shall possess the power of Thor." So both Thor and Steve believed that someone else wielding the hammer would rob Thor of his abilities.

This situation has already begun to change by the end of Age of Ultron, as Vision was able to use Mjolnir effortlessly. This doesn't have the same impact as a mere human being able to do so, as Vision is a combination of technology and mystical power, but Thor also learns that his own status is undiminished with his teammates even if someone else can lift his hammer.

At the climax of Endgame, none of those considerations mattered anymore. It was truly a life-or-death situation, not merely for Thor and the other heroes, but for the entire universe. Also, it had become clear since Thor: Ragnarok that Thor's own powers were not drawn from Mjolnir but from within himself. He can throw thunderbolts from his own body, and he has an equally impressive weapon in Stormbreaker for his striking, throwing, and flying needs.

So Thor's only reaction when Steve finally wields Mjolnir is relief, and a triumphant, "I knew it!", revealing that he had always suspected that Steve had previously refrained from showing his true strength.

Both theories make sense within the context of the overall story arcs of the characters, and both have had their adherents. However, in a recent question and answer session on Reddit, the Russo brothers (who directed Endgame) revealed that they believed that Steve was always able to use Mjolnir, and held back out of respect for Thor. 

Whatever the real truth is, it is a commentary on the power and unity of the storytelling in the Marvel Cinematic Universe that the question plays out and is answered over so many different movies. It is amazing to see a small seed planted in a moment of seemingly insignificant fun in one movie provide such a huge payoff four years and ten movies later.