I think people misunderstood my previous question, and that's my fault. However, I think it's a good time to test out something I've been working on.

You see, I've been watching Lobotomy Corp playthroughs and realized that there is a certain dramatic weight to being fragile. Not so fragile that a single hit from anything will do you in, but using kiting and The Hellevator to escape Gevura's heavy attack is definitely a cool move.

Powered armor is supposed to reflect that. Basically, it can protect against anything that can be sprayed and allows for inhuman sprint-bursts to help evade larger-caliber weapons (more precisely, their users).

But, I'm uncertain if it makes sense from a military perspective. Assuming people have access to modern tech (as in weapons) plus this "fast" powered armor, would its sprinting bursts be useful in most combat situations?

  • $\begingroup$ Usefull point of interest for "quick" acceleration/turning. $\endgroup$ Commented Jul 11, 2020 at 1:48
  • $\begingroup$ @user535733 I was thinking more along the lines of being able to do and sometimes go slightly above the speed of record-breaking sprinters while darting cover to cover. $\endgroup$ Commented Jul 11, 2020 at 2:09
  • $\begingroup$ @user535733 There's no reason why the guys in powered armor wouldn't have access to those, or use stealth for that matter. $\endgroup$ Commented Jul 11, 2020 at 10:52
  • $\begingroup$ What stops the enemies from getting the same armors? If they both have super fast armors then they just speed up a few thin s but everything remains the same. And if they have technology to make humans and heavy armors faster than bullets. Why can't they just make faster bullets? $\endgroup$
    – user76853
    Commented Jul 11, 2020 at 22:47
  • $\begingroup$ Recommended research: Cyborg (basis for movie and TV versions of The Six Million Dollar Man) and ManFac both by Martin Caidin. The latter refutes most of the stupid that was added to the former by the movie/TV industry, including running 60 mph. $\endgroup$
    – Zeiss Ikon
    Commented Sep 13, 2022 at 16:21

7 Answers 7


Won't work

Power armour has a human inside it thus can't move any faster than the human limbs contained within. At best you'll gain some speed due to additional leg height but that would be marginal at best.

Trying to move faster than a body is capable of will break the human inside.

Power armour is also a lot of mass and mass is harder to get moving and harder to stop. Think lumbering giants, not agile sprinters.

  • $\begingroup$ Then explain cars... Also why would moving a limb too fast break it? You are not bending bones but ligaments which are made to be bent... It's like bending a hair, no matter how fast you bend it....it won't break. $\endgroup$
    – user76853
    Commented Jul 11, 2020 at 22:44
  • $\begingroup$ Hell, the are bikes which go over 200 kilometers per hour... Why don't cyclists break their knees? There are people who can cut bullets with a sword slash, why don't their shoulders burst? And there are people who drop themselves from planes and reach absurd velocities. We are made of flesh, not spaghetti noodles. $\endgroup$
    – user76853
    Commented Jul 11, 2020 at 22:51
  • 2
    $\begingroup$ @Hol hoe Maybe because cyclist's legs aren't strapped to the wheels? Power armour responds to the movement of your own legs. The only way around this programmed movement where the armour moves on it's own independently of the wearer. To respond quickly enough to dodge bullets, you'll break bones and tear ligaments. $\endgroup$
    – Thorne
    Commented Jul 12, 2020 at 3:43
  • 1
    $\begingroup$ disagree with this argument. a powered exo suit can magnify the force exerted by the occupant, and increase mobility and overall speed without going to the extreme of injury. Enabling the user to exert less force of his own, to propel their mass forward to a degree that would constitute a considerable advantage does not equate to dangerously quick movements of the joints and limbs. The suite would do nothing to reaction times. pushup for example. unsuited they could perhaps do 20 in 60 seconds. Suited 1 per second or more would not be out of the realm of possibility. hardly bone breaking. $\endgroup$
    – Gillgamesh
    Commented Sep 13, 2022 at 17:41
  • $\begingroup$ Really? You're still limited by limb speed. Sure you've removed all the weight while doing a push up and you can do push ups faster but you're really not moving any faster than your limbs can move. Still not bullet dodging speed. What? Maybe a 5% increase? $\endgroup$
    – Thorne
    Commented Sep 14, 2022 at 1:45

Let's Say You Combine This... And This

enter image description here enter image description here

The first has more agility than is often thought, is immune to most small arms fire, weighs about 15 kilograms and costs about $3,000 per suit.

The latter has a surprising amount of controllability, top speed of 60 kilometers per hour, endurance time of 8 minutes of flight, weighs 44 kilograms, and costs around $440,000 per suit.

For some scale of costs, you can outfit 44 people with .50 BMGs for the same price

What you get is:

  • Immunity to small arms fire
  • Up to 8 minutes of "sprinting" at 60 kph
  • Possibly longer jet-assist "runs" at lower velocity

What can you do with 60 kph sprints?

The record for a modern rifle shot is 3.5 kilometers. At 60 kph, a jet-assisted power suit could close that distance fully in just as many minutes (3.5 min).

Or, combined with a rifle and a a portable fire-control system (I'm not sure if one exists), you could also stay at distance, fire on the move at the speed of an M1, but with the target profile of an infantryman.

Flat-out, you could cover 8 kilometers of uneven terrain, crossing chasms, ravines, rivers, and lakes safely.

For some idea of how useful that could be in a modern engagement, here's Galwan valley that China and India are currently disputing. Jet assisted powered armor could cross the entire engagement area in a few minutes.

enter image description here

  • 1
    $\begingroup$ I'm sure that by small arms fire you mean pistols, right? Because they can't stop a full rifle cartridges. Even with a 9mm rounds you can kill the person inside by repeated firing. So a submachine gun can chew this armor pretty quickly. $\endgroup$
    – Seallussus
    Commented Jul 11, 2020 at 19:16
  • 2
    $\begingroup$ Yes. Small arms = pistols in this answer. $\endgroup$ Commented Jul 11, 2020 at 21:56
  • $\begingroup$ Pity Jet assisted powered armor only caries 30 seconds of fuel at a time. Well you can always just hand your knight a parachute and push them out the back of a C130. $\endgroup$ Commented Sep 13, 2022 at 15:54
  • $\begingroup$ And the jetpack will let snipers (interpret broadly--they might be firing Javelins, not just bullets) get to positions that are pretty much invulnerable from the ground. This is going to make mountainous terrain very dangerous to pass through--the sniper takes their shot and flies away once their position is exposed and before artillery can land on their position. They can also spot for their own artillery. $\endgroup$ Commented Sep 14, 2022 at 1:27


And no power armor is. I've been over this before, and the consensus of the good people here, is that power armor is not viable outside of fiction. and the answers to this question i couldn't have said better myself.

I'm a paramilitary contractor, so in the field, such things would be a terrible investment. I don't care how cool it looks, but it only looks that good on paper. Taking my real world experience into account, The bottom line is that not only would power armor be useless in any kind of war, but it would bankrupt your defense or operating budget in a profound way.

tanks and drones are the far better investment.

and with science fiction, it's just stories. most who writes the screen plays were never there in the field, and thus they have absolutely no idea what they're talking about to begin with. No offense, but most of what you see on TV and on Film, is as opinion based as it is somebody's gilded cow-pie recipe, and will always be. That is until they begin showing reality or something that has a close enough semblance to reality to no longer be called a cow-pie. it looks good, but it's not reality. SO which is why i seldom watch most TV shows, although some suck less than others, and video games sadly are almost never spared from becoming a cringe-worthy cow-pie of a game that is largely opinion based and that I find hard to keep playing.

of course writers try their best, but almost all of us have to watch months or years of our work be turned into a dumpster fire by a media firm.

  • 1
    $\begingroup$ Well if you look realistically, all knowledge you have as a contractor is obsolete by the time we have working power armor. Micro sattelites can scan the ground with precision and long-range artillery big and small will take out targets. Small and hard to spot/distinguish would be key and armored vehicles obsolete. Small flying drones with small-arms or bombs can fly in and sabotage material or kill personel. War would be automated with cheap and small things, and humans would barely feature. So any future combat scenario is boring from a human perspective. My advice: accept in-universe laws. $\endgroup$
    – Demigan
    Commented Jul 11, 2020 at 19:34
  • $\begingroup$ I disagree--in an open area I agree that power armor is an automatic loser because it has a lot more armor surface than an equivalent tank. However, I believe there's one use case: operations in human spaces, especially human spaces with multiple levels. You want to conduct a boarding operation on a ship with tanks?! $\endgroup$ Commented Sep 14, 2022 at 1:32

The human body is fragile

There are fundamental limits to the forces you can apply to the human body. You could build a machine that could react faster than the human body (depending on how you define "power armor"). The problem is what would happen to the body inside. Moving quickly enough to dodge bullets would involve subjecting the body to huge g forces. Colonel John Paul Stapp, MD, PhD, volunteered as the human test subject in a series of tests in the 1950s to find the limits of the human body. As NOVA puts it, "He lost dental fillings, cracked a few ribs, and twice broke a wrist, but he survived." That's not an experience I'd want as a user. And there's emerging evidence from football researchers that repeated hits at lower g forces can cause brain injury.

  • $\begingroup$ You aren't dodging the bullet, you're dodging the user. $\endgroup$ Commented Jul 11, 2020 at 11:04
  • $\begingroup$ Plus, I wanted to ask something. Assuming the speed of the armor is only slightly faster than Usain Bolt, maybe by 0.1 m/s, would that still break the human? Because if it would, then I have to get back to the drawing board. $\endgroup$ Commented Jul 11, 2020 at 16:10
  • $\begingroup$ @Mephistopheles there are cyclists who can reach 200 kilometers per hours... Multiply that by 1.6 if use mile. And those cyclists don't break their knees as if they were made of noodles. $\endgroup$
    – user76853
    Commented Jul 11, 2020 at 22:55

Would its sprinting bursts be useful in most combat situations?


Although a lot of military operations are using drones, combined arms, navies, high-performance aircraft and intelligence, there is still an element of 'boots on the ground' in particular in peace-keeping roles or occupied territory - or asymmetrical or special-forces warfare.

Such roles are also often unreachable for vehicles.

In these situations it is better to be light-weight, dispersed, and well-informed. The ability to speedily zip to and from areas has the following benefits:

  • Greater range of special force and infantry reach from drop points
  • Quicker arrival of reinforcements in the event of an incident
  • Cover more ground in less time on patrol
  • Less fatigue and more energy for encounters
  • If wounded, faster travel to medical facilities for treatment
  • Easier, faster and less detectable reconnaissance for better intelligence

If there are no costs, these are all benefits.

However, it always does come down to costs. Not every soldier can wear body-armour, nor is the best equipment often used. There are normally trade-offs for older but more reliable equipment, or weight vs endurance too. These compromises must be balanced for each mission.


Lets define speed enhancement. Sprinting or sustained? There are going to be two limit pathways for faster-than-human power armor. 1. Human frailty and 2.User interface responsiveness.

If you want the armor to make the human run faster, there is a limit to how fast human limbs can move. (Obviously we arent talking about sit down mechwarrior types, but personal suit types). If you want the suit to enhance reaction time, then you have to have a predictive interface that can predict movements faster than the human can react.

The first problem I think can be assisted by changing how the suit wearer moves. If the suit had a strong actuator in the ankle, then maybe a "leaping" movement would allow to suit to speed up the wearer while not overstressing the human within.

The second type is still in the deep sci-fi realm. It would require either a true AI interface or some kind of brain plug in to the suit could react to thought rather than movement. Either way, it would be cool to see.


From the word go you have to assume that these powered armor suits are cost/effective enough to be useful. Just like we dont question how most sci-fi uses WWI and WWII space combat because it gives us a framework to work with. But we also dont question "hard" science like The Expanse has us believe that combat is still done by humans at the controls, rather than it being fully automated. The Expanse is one of the hardest science series there is, but in the end you just have to believe the limitations it puts on computer technology and human intelligence by the time we reach that technology capability.

Would fast powered armor be useful? Absolutely and without a doubt. Powered armor is relatively small, and if you wanted armored you would have brought an armored vehicle. So powered armor has to rely on its strengths: the small size and maneuverability offered through urban area's, forests and steep mountainous terrain. The problem with humans is that they'll tire out and have limited speed. Powered armor would help them keep up their stamina. Normal doctrine when combat is started is to drop just about everything you are carrying except the things you are about to use. Because your stamina is as important, if not more, than your aim. With these suits you can keep going for longer while carrying more. If it also protects you from things like shrapnel all the better!

Now you want this armor to "dodge the user". That means that if they aim at you, you can evade their aim well enough so they'll miss. Staying out in the open is just stupid in my opinion, but racing from cover to cover, using their relatively small size and high speed and maneuverability that only infantry have to avoid getting shot? That sounds extremely plausible.


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