I am referring specifically to the MCU version, but if it's ever shown in the comics continuity that will work too.

During the films there are times when Cap will either sling his shield on his back or pull it from his back very smoothly, without pulling his arms through the straps in the shield. Is this just for "Rule of Cool" or is there an actual way he's attaching and removing it from his back? Is it maybe magnetic, a hook and loop, Hulk level velcro? You can clearly see on all three versions of his uniform he wears some kind of shoulder holster apparatus that's not attached to the shield itself, but it just looks like two loops of leather and a metal bracket in the center of his back. The forearm straps would have to remain tight in order to maintain a snug fit for protection when in use, so I don't think he's loosening them and sliding his arms through in such a fluid motion.

  • 2
    Velcro may approach Hulk-level all on its own. Commented Jul 16, 2014 at 13:54
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    Vibranium has a rare elemental property where it tends to move towards cooler areas. This property is known as the "Rule of Cool".
    – Zibbobz
    Commented Jul 16, 2014 at 14:54
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    @Zibbobz perhaps that's why the majority of it is found in a nation who's king is one bad mother(SHUTYOMOUTH!!) I'm just talkin about Black Panther! (I can dig it!)
    – Monty129
    Commented Jul 16, 2014 at 17:13
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    We know that the shield is likely to be ferro-magnetic. Why not use an powerful magnet and electromagnetic combination. The magnet could line it up and ensure it lands in the right spot, while the electromagnet could activate by weight and be deactivated by the right motion. This would give you the exact behavior we see in the movie. He slings it to his back and it locks into place. He grabs it and it slides into his hand. The electromagnet could even be controlled by a button on his glove or belt. Commented Aug 5, 2014 at 0:06
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    I read this as harness (v) work (n), not harness (n) work (v), and was disappointed this was not about it absorbs and redirects energy. Commented Aug 25, 2014 at 15:09

6 Answers 6


The shield system used in Captain America could be facilitated without a whole lot of super-science using an electromagnetic system mounted inside the shield or using the shield itself.

  • If Vibranium is ferro-magnetic (and there isn't any reason to think that it isn't since it is likely a vibranium/other metallic alloy) then the shield could simply be held in place with an electromagnet linked to either a belt control or if that is too burdensome, a glove interface where when the shield is grabbed and pulled, the electrical charge is released allowing it to be thrown.

  • When the shield is placed back into position and released, the electromagnet is activated and the shield is held in place.

This system makes the most sense since we don't see Captain America strapping the shield back on, like he does in the comics, and there is no visible harness being used in the movies.

enter image description here

Here is a clip showing the inside of the shield from the awesome elevator fight scene. Note there are arm clips for his arms and hands and nothing else.

  • If the shield is not ferro-magnetic, then a shaped and balanced insert placed on the inner surface of the shield can be used to hold the shield in place. The weight should be minimal and able to be corrected for with a bit of practice on the Captain's part.

I support this hypothesis with the speed at which the shield is placed on on Cap's back. There isn't any other means by which the shield could be used and replaced with such speed. At 1:20, he throws the shield and strikes an enemy. By 1:21 the shield is back on his back and he is off to fight again.

  • What are those four diagnal bars coming off the arm straps I wonder. Magnets, maybe?
    – Monty129
    Commented Aug 7, 2014 at 14:04
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    Magnetism is highly plausible seeing as Cap uses a magnetic retrieval system in AoU.
    – user71772
    Commented Nov 17, 2016 at 16:22

This is mostly an educated guess based on experience building practical props. I haven't been able to find any interviews or articles discussing the practicality of wearing the shield yet.

As far as the movie goes, I think the only method that makes any sense is a magnet. In the comic version, the straps of the shield are often visible over Cap's shoulders, indicating that an arm goes through each strap. In the movie, though, he just slaps that thing on his back and keeps going. It's obviously separate from the straps seen on the uniform shoulders, which is the harness you described.

If the metal bracket on his back had a magnet strong enough to hold the shield in place, it would snap on fairly effortlessly. The problem would be getting it to snap in place the same time every time. Of course, that's where the movie magic comes in - we don't see the numerous takes where Chris Evans went to slap that shield on his back and it clasped in place crooked or went flying off to hit a crew-member.

I would also assume that they have two versions of the shield, with one being a bit flatter than the "hero" version which is pretty curved. The curved version we see in several close-ups would be difficult to attach via magnet, since the center would be the furthest point away from the magnet. A flatter version with only a moderate curve (or a non-concave center and curved edges) would snap into place much easier, and would be used for the separate shots where he puts the shield on his back.

If you're interested in further reading, here's an RPF discussion where the topic is looked at from a more practical angle:


UPDATE: So far I've only been able to find one production photo that shows the back of the suit, and this is a stuntman so this version of the shield harness may be for looks only. If it IS functional, it supports either the magnet theory (probably located in the flat center section) or the slot/notch theory discussed in the forum link above.

CA2 Uniform from behind

  • A magnet could make sense, except it would have to be a pretty strong magnet to hold the shield perfectly in place while he's doing things like jumping out of a Quinjet, or landing spinning back kicks, but still allow him to draw it off his back smoothly without having to wriggle and fight to get it to release. I think the comic version has a second set of shoulder straps that aren't always shown, but I can't confirm that or not.
    – Monty129
    Commented Jul 17, 2014 at 20:46
  • @Monty129 Well, Captain America does have enhanced strength...
    – Izkata
    Commented Jul 17, 2014 at 23:09
  • The magnet doesn't necessarily have to be in the center where the curve pushes it away from the body, it could be on the rim and connect the edges to his shoulders and hip/butt area
    – Izkata
    Commented Jul 17, 2014 at 23:10
  • Is Vibranium even ferromagnetic? Then again, the thing comes back to it's owner like Xena's Chakram, so maybe it bonds with residual energy from the Vita rays...
    – BMWurm
    Commented Jul 30, 2014 at 23:33
  • @BMWurm the shield isn't composed entirely of Vibranium, it's a Vibranium/Stainless steel alloy. As for the "boomerang" effect it's all to do with Cap's understanding of spacial geometry, accuracy, and ricochet that allows him to bank shot it off walls and people and return to him.
    – Monty129
    Commented Aug 8, 2014 at 12:46

I noticed in the second movie, all of "The Winter Soldier's" holsters were magnetic. There's nothing covering the firearms like a conventional holster, they just kinda stick to him where the harness is. He wears a similar shoulder rig to Caps and he has that small SMG on his back. He has a drop holster on each hip with his handguns stuck in place too.

Based on this, a magnetic harness for Caps shield seems plausible.


Listening to the sound it makes whenever he slings the shield on his back as well as the "snapping" nature in how it looks when he does so leads me to believe the creators want you to think its magnetic. This doesn't prove that the practical application is actually magnetic as foley artists could add whatever sound they were directed to add in. But it does make sense that the prop was actually built with a magnet as well. If the shield was made light enough it wouldn't be much of a problem with the proper design and magnet placement.

  • Hello Steve and welcome to the Sci&Fa SE. Please refrain to use answers for speculations or to add details to previous answers, that's what the comments are for. Use the tour under the help button to learn further about this awesome community. Cheers ! Commented Mar 18, 2015 at 8:27

A magnet makes the most sense, although it might not be placed at the center of the shield. The back of the harness rests towards the top of Cap's back, suggesting that the magnet could be placed towards the top of the shield, allowing him to snap it in the right place every time. Also, the shield never extends above the top of Chris Evans neck, when if you strap a 27 inch diameter circle to the upper trapezius area, it would extend far above his head. This also eliminates the issue of the center of the shield being the furthest away.


I always assumed Cap has a magnet on his back and that that's how it is supposed to work in the movies.

However, I just read Magneto has no power over Cap's shield. Either the movies did not take this into account or they are hoping they never meet because if they do SOMEBODY has some double talking to do.

The again maybe it is a Stark reverse repulsor device...

  • 1
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    – DavidW
    Commented Feb 25, 2021 at 1:28
  • It's not strictly true to say that Magneto has no power over Cap's shield. There was an issue where he said that, but he was shown to move Cap's shield with his power in a prior issue, and a clone of his did the same in a later one. Cap's shield is partly made of a steel alloy dubbed proto-adamantium, so it makes no sense that it wouldn't be magnetic. Standard adamantium is definitely magnetic. See my answer to another question here for relevant scans. Commented Feb 25, 2021 at 1:29