There have absolutely been armour in which leather was used as material, but the RPG leather armour is mostly fictitious.
Leather armour is not flexible and supple. That's just leather clothing and protects about as well as an overcoat.
2/16
Leather that has been treated (boiled or baked, we don't really know the exact process) is hard and resembles ceramic plates or hard plastic more than the flexible leather we use in clothing.
But hard plate sounds good for an armour, right?
Well, yes and no.
3/16
Hardness is definitely a merit, but leather as a material poses some serious limitations.
1) You can't really repair leather armour
Cloth can be sown, metal can be welded and reforged, but apart from some very dubious glueing, there isn't much you can do for leather.
4/16
You'd have to replace entire sections of the armour in their entirety, so field repairs are out of the question. Not a great feature for any professional soldier at least.
This doesn't preclude ceremonial use, but that takes it out of the realm of real armour altogether.
5/16
2) Treated leather isn't really better than other, easier to maintain options
Leather armour is just that. A carapace of hard plastic, essentially. Does it protect you? Yes, of course. Does it protect you better than cloth armour or mail? Not really.
6/16
With hardness comes brittleness, so leather armour can't take blunt impact nearly as well as cloth or mail. It probably can withstand cuts better than cloth armour, but mail is essentially impossible to cut through anyway. Also both other types are much easier to repair.
7/16
So was leather armour used at all then?!
Well, here's the thing: we don't really know for sure.
Leather is organic material, and as such is highly susceptible to rot, decay, and degradation. We don't really have much in the way of evidence, because it doesn't survive.
8/16
Metal armours have a wealth of archaeological information, because they are more resistant to decay. With leather that simply isn't possible.
The records that we have on leather armours suggest that it was likely used at some point, but to what extent, we have no idea.
9/16
Was it widespread? Probably not.
Leather doesn't offer any real benefits over other, easier to make and maintain armour types, so it's not an attractive option for either professional military or militia. They'd make do with gambeson, or splurge on mail if they could.
10/16
Lastly, I'd like to address the single most dumb idea RPGs have put forth on this topic – studded leather.
If we're talking soft leather clothing, a few rivets won't add any measurable amount of protection, and will just make blunt impact more dangerous to the wearer.
11/16
If it's proper leather plates, you're essentially weakening the structural integrity of your armour for a fashion statement. I mean, I love Cyberpunk as much as the next gal, but historically, when people's lives were at stake, function usually superseded form.
12/16
Now I don't rightly know how this idea of a Hollywood fashion reject as real armour got started, but my pet theory, and one that at least would make sense to me, is that it's a misinterpretation of brigandine armour.
13/16
Brigandine is usually made out of leather (soft leather, not treated plates), with metal plates or scales riveted on the inside overlapping each other. This makes for essentially a plate armour that's quite flexible, while also affording excellent protection.
14/16
The thing about brigandine is, that on the outside, it literally looks like studded leather. With the slight exception that it's actually a metal plate armour, and the "studs" are just the rivets attaching the plates to the leather exterior.
15/16
I have no idea if this is actually what happened, but it's at least a very reasonable misunderstanding if that is the case. Or it could be just something Gygax and pals yoinked out of their collective butts to fill the AC void between leather and mail shirt. 🤷🏼♀️
16/16
