Let's take your typical dragon- 12m long, reptilian, claws and horns, flies using big bat wings and breathes fire. Assuming that the dragon in question has wings and muscles big enough to get them off the ground with a stag in their claws and a human on their back, how much armour could the dragon wear? What material would be best- could you make a kevlar dragon-suit?

For the record, the dragons are employed by police/military, but I'm not asking about need- I'm asking about their ability to wear armour.

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    $\begingroup$ would... would a dragon need armor? Are their scales not like tenfold shields, teeth like swords, claws spears? $\endgroup$ – Feaurie Vladskovitz May 21 '15 at 10:00
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    $\begingroup$ Stop promoting unrealistic standards for dragons! They can't all be Smaugs. $\endgroup$ – Titanide May 21 '15 at 10:27
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    $\begingroup$ Considering how unreasonable the idea of a flying dragon already is, the only real answer is "however much you want". $\endgroup$ – Erik May 21 '15 at 10:29
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    $\begingroup$ What you usually find in riots are rocks, clubs, and tear gas. In more violent events, you would see Molotov cocktails and maybe some handguns. Given that a dragon's scales are (in most lore) harder than any metal wrought by man and dragons are impervious to fire, I fail to see how wearing armor will advantage the dragon over the weight and loss of mobility. $\endgroup$ – Frostfyre May 21 '15 at 12:21
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    $\begingroup$ In most lore yes, but my dragons aren't any more damage resistant than the average reptile. And the question isn't about need, it's about ability. $\endgroup$ – Titanide May 21 '15 at 12:22

How much armor could such a dragon wear? As much as you want it to.

Anything that big can wear whatever armor it wants. Humans are known to fight in some pretty heavy armor. Dragon Skin (yes, it really is called that) has been reported to weigh 47.5 lbs. (21.5 kg). The U.S. Army-issued Interceptor armor weighs only 28 lbs. (12.7 kg). According to the Army's physical requirements, the Dragon Skin armor weighs about one-fifth the highest denoted weight for a human.

If your dragons are winged quadrupeds, they should be able to support armor that is up to one-half their own weight while on the ground (four legs allows greater carrying capacity). They likely wouldn't be able to fly while wearing it unless they possess some form of augmenting magic. Which, let's face it, is an extremely likely possibility, given that we don't find dragons in our world (nuts).

What should the armor be made out of? Anything you want to make it out of. Modern armors are made from synthetic materials and layers, such as Kevlar and Dragon Skin. Medieval armors were made from leather and steel. Ancient armors were made from animal hides and even bone.

Of course, as the discussion in the comments is indicating, you probably don't need them to wear armor. If you're using a dragon to quell a riot, you're probably doing it wrong.

  • $\begingroup$ Okay, that actually answers my question. Thank you. $\endgroup$ – Titanide May 21 '15 at 12:50
  • $\begingroup$ @Titanide Happy to help! $\endgroup$ – Frostfyre May 21 '15 at 12:55
  • $\begingroup$ @Titanide If this answers your question, you should mark it as such. $\endgroup$ – Edit Your Profile May 21 '15 at 13:37
  • $\begingroup$ "Winged quadrupeds" means six limbs with two of them being wings and four being legs, correct? Do you mean they have four limbs and the front two are wings? $\endgroup$ – Pyritie May 21 '15 at 14:38
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    $\begingroup$ I like this answer. It's a polite way to say, "You're already making incredibly implausible stuff up, what do you need us for? Make up the rest of the incredibly implausible stuff yourself." jeb.biologists.org/content/130/1/235.full.pdf and books.google.com/… $\endgroup$ – Adam Davis May 21 '15 at 15:36

Quadrupedal armor is a very real thing, and while we don't have any flying quadrupeds that we would want to put armor on, it's not hard to imagine a design for such armor based off of the already-existing animal armor in the world.

They would have to cater to the specific needs of a dragon though - space for wings to come out and effectively create lift would be a primary concern. As would weight - too heavy an armor and rider, and a dragon wouldn't be able to fly at all (Not that non-flying dragons can't still be fearsome).

But the biggest issue you need to address is: Why would a dragon need armor in the first place? They are, after all, already covered in scales. Perhaps your dragon's hide isn't as impenetrable as some fictional counterparts, so armor would make sense. But if they have any protection from their scales at all, you'll have to justify why they would ever wear armor (bladeproof vs. bulletproof might work).

  • $\begingroup$ By my reckoning, their scales are only a bit stronger than a typical lizards, so armour's a need $\endgroup$ – Titanide May 21 '15 at 14:45
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    $\begingroup$ quadrupedal, not quadriplegic :D $\endgroup$ – Pyritie May 21 '15 at 14:55
  • $\begingroup$ @Pyrite Autocorrect. For some reason "quadrupedal" is not recognized as a word. $\endgroup$ – Zibbobz May 21 '15 at 14:56
  • $\begingroup$ @Titanide That does raise the question of how a dragon's body is held together, but I'll assume that's either explained or handwaved. Regardless, if that's the case, then yes, they can wear armor and armor like what they would wear has been created before. $\endgroup$ – Zibbobz May 21 '15 at 14:57
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    $\begingroup$ Your first link is not really applicable. Maybe this one is better: worldwarriorbg.wordpress.com/2011/12/03/war-elephants $\endgroup$ – fredsbend May 21 '15 at 22:02

Let us compare to real world flying animals. An eagle can carry about 1/3 its weight while in flight, at least for shorter distances.


Let us assume that in order to fly, despite its size a dragon must be very light. At 12 m long let us give it the weight of a horse. 380 -550 kg.

1/3 of that is 128-180 kg carrying capacity in nature for short distances.

With selective breeding and training we could assume they can extend the duration they could carry this weight to a more useful distance or time. (Even short range flight would be incredibly useful though)

So any Armour that does not restrict movement or hinder aerodynamics that gives a total load less then 550 kg could be used.

Hardened leather would be best protection to weight ratio. However be aware there is nothing non magical that will protect from the force of a Batista bolt. (Giant crossbow) Since standard cross bows could pierce even plate mail.

Edit: What type of armor should they wear?

This depends largely on your world and what they need to be concerned about.

Are dragons smart animals? Then the pilot is the most important part. Once he dies the dragon runs amok. (Like elephants) Most of your armor should go to protecting the pilot.

Where does the biggest threat come from? Do most dragons die in air combat? (dog fights) If that is the case most of their armor would be in the back and rear since that is traditionally where most dog fight kills come from.

Are dragons primarily used for dive bombing? Then you might want supper heavy armor but only on the front (what is exposed to the ground in the steep dive). Make it out of angles to focus more on deflecting shots instead of stopping. Make it arrow dynamic and you will even dive faster. Perhaps instead of armor they would take some type of shield for this? Then they could drop the shield as a weapon at the bottom of their strike to add to the confusion. Then they would be lighter immediately after and able to escape more quickly. Do remember though, they are flesh and blood. To much force/weight in this decent and the dragon might break off its wings trying to stop.

I think for police dragons hardened leather is best. But you will have some forcible entry dragons that are heavily armored and stick to the ground.


tl;dr: If you've already hand-waved in a 12m long, massive, winged, fire-breathing, flying creature, armor really isn't much more of a stretch, so put whatever you want on them. Dragons are already so entrenched as a fantasy genre staple that nobody is looking too closely at weight ratios.

The reason dragons—or any other significantly sized, winged flying animals—don't exist has to do with size to strength and weight to wing surface area ratios and metabolic constraints. The real question is could a naked 12m long dragon fly at all, and, in the absence of magic or other hand-waving, the answer is absolutely not.

The first issue is that strength doesn't scale up as quickly as weight due to the cube-squared problem. A good discussion can be found here, which I found via this answer.

The gist is that muscle strength is proportional to the surface area of the cross-section of the muscle strand, a two-dimensional measurement, so strength will vary (roughly) with the square of size. Weight depends on the volume of the creature, a three-dimensional measurement, so weight will vary with the cube of size.

The result is that the highest strength to weight ratios are found at the smallest scales. An ant can lift and carry 50 times its own weight, I can lift and carry only 1/4 to 1/2 of my own weight, and the very largest dinosaurs could likely only barely lift their own body mass. (The very largest animals, whether modern or prehistoric, were aquatic, as they are too big to lift their own mass.)

Now, your dragons are 12m long (about 39 feet), which is about the length of a T-Rex. Depending on who you ask, tyrannosaurs weighed between 5.4 metric tons (6.0 short tons) and 6.8 metric tons (7.5 short tons). I wouldn't think it unreasonable to assume that a dragon of similar size would fit somewhere into that weight range, but that means we are dealing with an animal with the length and mass of a school bus. How could it fly if it can barely keep its body off the ground with its legs?

When the animal is winged, another limiting ratio comes into play at takeoff: mass to wing surface area. As discussed here, the wing surface area required to provide enough lift to get off the ground will grow much faster than body weight as a creature is scaled up. Small birds can get away with small wings. Bigger birds require a much larger wingspan for their mass.

How large?

Ruby-throated hummingbirds max out at 0.006kg weight and 0.11m wingspan. American crows max out at 0.62kg weight and 1m wingspan. Mallards max out at 1.58kg weight and .98m wingspan. Peregrine falcons max out at 1.5kg weight and 1.2m wingspan. Bald eagles max out at 6.3kg weight and 2.3m wingspan. Wandering albatrosses, which have the largest wingspan of any living bird, max out at 12.7kg weight and 3.5m wingspan.

Of course, most dragons are depicted as featherless, with wings more like those of bats or pterosaurs than those of birds. This fact actually makes a flying, massive dragon even less workable, as bat's wings are very thin and fragile, composed of delicate skin stretched over bones with low mineral density (and thus high fragility). They rip and tear easily and would be even more prone to damage as you scale them up.

Here is a table with bird and bat wing loadings which shows that even the largest bats have a mass-to-wing-surface-area ratio lower than that of a hummingbird.

It turns out feathers are an efficient way of increasing wing surface area without adding much weight, but even feathers run into limitations; body mass in birds is actually constrained by how long it takes to replace flight feathers during molting.

So let's look at the quetzalcoatlus, very likely the largest creature to ever fly. A pterosaur, it massed over 200kg with a wingspan of up to 12m.

We're still not even sure how quetzalcoatlus got off the ground or whether they were even capable of more than long glides from a high starting point and relied on thermals to climb.

But, making the completely arbitrary assumption that a 12m long dragon masses at least in the ballpark of a similarly sized Tyrannosaurus Rex—let's just call it 5000kg—that is still 25 times the mass of quetzalcoatlus. What kind of wingspan would our dragon need to have?

This article attempted to (very roughly) predict the required wingspan of a human-sized (70kg) bird.

This article on wing loading says that the maximum for bird flight is 25kg body weight per square meter of wing surface area (Wikipedia backs it up). It also mentions that an elephant weighing 3.5 metric tons (which is actually small for an elephant according to Wikipedia) would need a wing surface area of 1750 square meters to take off. That's larger than six tennis courts, and basically requires the wings be made of aluminum or some other man-made material just to not buckle under their own weight. A dragon's wings would have to be prohibitively massive.

The final issue is metabolism. Dragons run into both the huge caloric requirements of dinosaurs (or any other multi-ton creature) and the even more demanding metabolic needs of flight. You don't get giant apex predators without giant prey (as with dinosaurs) or highly efficient feeding on concentrated food sources (like the way blue whales gorge on up to 3.6 metric tons of krill in a single day).

So where is your dragon getting his calories?

My brief research into metabolic requirements for flight determined that the topic is complicated. Really complicated. I'll come back to it when I have more time.

In conclusion, biology is all about tradeoffs, and dragons, envisioned as you describe, don't make any.

In earthlike gravity, air density, and physics, it's unlikely they could exist and fly at the scale you suggest even if designed expressly for that purpose. With or without armor.

On the other hand, we've identified dragons' only natural enemy: the square-cube problem!

  • $\begingroup$ This does not answer the question. $\endgroup$ – Titanide May 21 '15 at 22:52
  • $\begingroup$ I wouldn't take the size-weight ratio of earthbound reptilians. If you compare Birds or Bats with reptilians of the same size, they are much lighter, because of hollow bones and overall very light and skinny build. I recon a Dragon would have a big evolutionary advantage by being very agile and light. - But on the other Hand, the biggest Birds on earth (eagles, giant vultures) already need a high starting place and upwind to get airborne and can't really start from the ground lifting some weight.... $\endgroup$ – Falco May 22 '15 at 9:42
  • $\begingroup$ So a dragon would probably need a Huge tower or Mountain to even get airborne, he would jump down and need a lot of upwind (or create some by flying over lava/setting things on fire) to even stay up. So the biggest Danger for a dragon would be being grounded/getting close to the ground... $\endgroup$ – Falco May 22 '15 at 9:44

Concerning a kevlar suit: I would assume that a dragon that breathes fire has some kind of natural protection against fire inside his throat / mouth, and it would be pretty surprising if his throat was more resistant to fire than his scales. So fire protection shouldn't be as much of a priority as resistance to piercing/slashing.

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    $\begingroup$ About fire proofing it depends on how they breath fire, if they spray fuel and then ignite it then it only needs fireproofing on the snout and enough training to not swallow the flame. $\endgroup$ – ratchet freak May 21 '15 at 10:41
  • $\begingroup$ @ratchetfreak Even then, their hide would need some protection from fire in the event they pointed their head at someone/thing under/next to them while spitting. Nature tends not to favor creatures that kill themselves in self-defense. $\endgroup$ – Frostfyre May 21 '15 at 12:23

Dragons are probably far heavier than the armor you're placing on them, to the point of being relatively insignificant to them. For comparison, an elephant armor weights around 160kg, with the elephant itself weighting around 7,000kg. As long as you're wearing them with anything weighting as much as conventional materials for human armor, it shouldn't be cumbersome to them.

As for those wanting a need to equip them with armor, it can be used as protection against Dragonslaying equipment; almost every setting with dragons on it also has some equipment that magically inflicts extra damage to them, but is not any better than traditional swords against mundane armor.

Since these dragons are being used by the military, they would expect foreign armies to develop some Dragonslaying weapons and create specialized troops just to deal with dragon-based regiments. It's just as anti-tanks units in modern warfare; clumsy against foot soldiers, but needed against any enemy bringing tanks against you. If you can stop such specialized weaponry with mundane armor, you're a fool to not suit your dragons with it.


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