Natural armor scaling*

[TuggyNE]

So, I've seen advice for homebrew monsters to set NA to CR for starters and then adjust from there, and that certainly seems to roughly fit how WotC calculated NA for pretty much most creatures. This bugs me, because it seems quite hacky and largely unrelated to the actual meaning of natural armor. Are there any good solutions for this, though?



*How clever, right?

[Flickerdart]

I'm not sure what the problem is, but I just wanted to say that I found the pun amusing.

[Inferno]

I'm pretty sure the issue at hand is that NA scales more by CR and less by logic.
Like lets say, the Frost giant: 9NA, despite appearing to have fairly normal humanoid skin/fleshy bits. (Frost giant could be a lousy example, say his flesh is half frozen or what have you. Its what came to mind first, I'm not looking for a better one.)

Not sure what I'd do to fix it if it bothers you all that much, dropping the NA and buffing Health comes to mind.

[TuggyNE]

@Flickerdart: thanks. :smallwink: It was actually unintentional, but I noticed it and thought I'd leave it in.


I'm pretty sure the issue at hand is that NA scales more by CR and less by logic.

Yes.


Like lets say, the Frost giant: 9NA, despite appearing to have fairly normal humanoid skin/fleshy bits. (Frost giant could be a lousy example, say his flesh is half frozen or what have you. Its what came to mind first, I'm not looking for a better one.)

Most of the monsters could be retro-justified with some more-or-less suitable excuse. However, I'm not convinced that the reason for that natural armor would ever have been thought of or considered had it not been necessary to pad the numbers. To use the language of scientific theories for a bit, it's not elegant, since it makes no actual predictions; "natural armor" is code for "the stuff that the theory of AC doesn't otherwise account for". Which, not to put too fine a point on it, is FAIL.


Not sure what I'd do to fix it if it bothers you all that much, dropping the NA and buffing Health comes to mind.

Hmm. Well, the various ideas of BAB-based defense occurred, but those tend to be a bit wonky math-wise, so I was hoping there was some clever way to fix both the math and the theory.

Perhaps a better way would be to more directly represent the idea of parrying blows as a thing that creatures can, in general, do.

[Andezzar]

Just strike the "resulting from a creature's naturally tough hide" from your mind. Continue to call that form of defense Natural Armor or change it to Natural Defense or something like that. Generally AC can mean a lot of things. It can mean that you are less likely to be hit or that the hits, that do occur, are less likely to do significant damage. A tough skin seems to help only in the latter form. Once you think of the natural defense as incorporating both methods it becomes a lot less weird.

So the frost giant would have more or less normal skin but is instinctively of either avoiding blows or letting them land on sections of his body that will not inconvenience him much.

[TuggyNE]

Just strike the "resulting from a creature's naturally tough hide" from your mind. Continue to call that form of defense Natural Armor or change it to Natural Defense or something like that. Generally AC can mean a lot of things. It can mean that you are less likely to be hit or that the hits, that do occur, are less likely to do significant damage. A tough skin seems to help only in the latter form. Once you think of the natural defense as incorporating both methods it becomes a lot less weird.

Well, I already get that touch AC is "it didn't even graze you", so if an attack hits touch AC but misses due to natural armor, it's reasonable to suppose it wasn't a sufficiently downright blow to go through the skin, either because it simply didn't have enough force (although that's more DR's domain) or because it wasn't at the right angle.

At any rate, that's how it works for things with actual thick hide/scales/whatever. Something like an eagle/giant eagle (+2 NA, why?), air/fire elemental (+5 NA from medium to greater, why and how?), aboleths (7 NA, despite having, if memory serves, no skin at all), unicorns/pegasi/centaurs/ponies/horses/warhorses (6/3/3/2/3/4 NA respectively, despite being essentially the same thing), vampires (+6 NA!), ghouls/ghasts (+2/+4 NA, despite being basically humans), zombies (which have a size-based adjustment, to make sure their size modifiers to AC get canceled out), doppelgangers (4 NA, despite, again, being basically human in pattern), and lots of others all make me wonder what's going on.

My faith is restored, a little, by the observation that MMI oozes at least seem to have no natural armor at all.


So the frost giant would have more or less normal skin but is instinctively of either avoiding blows

That's a dodge bonus, and should be labeled accordingly.


or letting them land on sections of his body that will not inconvenience him much.

That's probably natural armor, yes, although it might just be HP.

[hamishspence]

Ghouls might have it due to the "rubbery skin" which is first mentioned in the Lovecraft stories.

Birds have feathers- a big bird's feathers might make it harder to connect solidly.

And so forth.

[Jeff the Green]

The unicorn, vampire, ghoul, and ghast can plausibly be explained as magically toughened flesh. Or perhaps the unicorn has an aura that makes weapons become blunt and soft as they touch it so only the hardest/most accurate strikes go through.

But you're right. And I'm glad you pointed it out. I've been trying to design some fay and their AC was turning out all wonky; this explains it.

Edit: Semi-ninjaed. (Ascetic stalkered?)

[Andezzar]

The unicorn, vampire, ghoul, and ghast can plausibly be explained as magically toughened flesh. Or perhaps the unicorn has an aura that makes weapons become blunt and soft as they touch it so only the hardest/most accurate strikes go through."It's magic" and "a wizard did it" can explain almost everything.

I looked around and found that AC is only supposed to change how easy it is to hit someone, and not also what effect a hit should have. So neither thick skin or a layer of leather, steel or other resilient materials should actually increase AC, and hits that have little or no effect (which is how worn armor and probably thick skin as well work) should not exist. There is the dysfunction. A guy in Full plate being more adept at not getting hit than a guy wearing regular clothes is pretty weird.

[TuggyNE]

Birds have feathers- a big bird's feathers might make it harder to connect solidly.

As noted: sure, you can come up with explanations that aren't entirely wrong or implausible. But you can't come up with explanations that absolutely necessitate, or even really strongly inform, the numbers they gave; at best, you can make a reasonable argument after the fact, but there's not enough of a consistent pattern to justify any one formula.

(Also, a giant eagle having feathers that make it substantially harder to hit than a regular eagle just seems weird. Eagle feathers are eagle feathers!)


But you're right. And I'm glad you pointed it out. I've been trying to design some fay and their AC was turning out all wonky; this explains it.

Glad to help. :smallwink:


"It's magic" and "a wizard did it" can explain almost everything.

Yeah. They're just unsatisfactory, because they're on the level of "because I say so" or "because that's how the gods formed the world". They aren't answers, they're just stop-asking-questions-man-was-not-meant-to-know.


I looked around and found that AC is only supposed to change how easy it is to hit someone, and not also what effect a hit should have. So neither thick skin or a layer of leather, steel or other resilient materials should actually increase AC, and hits that have little or no effect (which is how worn armor and probably thick skin as well work) should not exist. There is the dysfunction. A guy in Full plate being more adept at not getting hit than a guy wearing regular clothes is pretty weird.

Not really; it's a lot harder to find a weak point in good plate than in ordinary mail, and if you don't find a weak point your hit does essentially nothing. Greater strength and skill helps you to get past active defenses, make use of lesser vulnerabilities, and more fully exploit what vulnerabilities you find.

I'm not looking to make all AC into touch AC, even if that might be an interesting project for a different system.

[Chronos]

An attack that goes CLANG against your opponent's breastplate is not considered "a hit that does almost nothing", it's considered "a miss". A hit versus a guy wearing a breastplate means that your sword slipped through a gap in the armor, or maybe poked a hole clear through the armor, or maybe hit the armor so hard that you shook up the guy inside enough to damage him anyway (OK, that last one is more plausible for a warhammer than a sword, but that's made up for by the fact that it's harder for a warhammer to slip through a chink).

Natural armor is supposed to work basically the same way, except it's growing out of the creature. So a miss slides off the scales or gets tangled in thick fur or whatever, and a hit slips in between the scales or whatever.

[Crake]

For much larger creatures, such as the frost giant example, I would think that natural armor also includes the thicker layer of skin, meaning a shallow cut has less of an effect, since it needs to cut through more flesh to get to the vulnerable parts of the body.

[KillianHawkeye]

(Also, a giant eagle having feathers that make it substantially harder to hit than a regular eagle just seems weird. Eagle feathers are eagle feathers!)

The difference is that the feathers on the giant eagle are BIGGER! :smallamused::smallbiggrin:

[Flickerdart]

A giant eagle is a magical beast, not simply a big eagle. It's possible that they have denser feathers or something.

[Agincourt]

The problem with expecting Natural Armor to be predictable is that none of these creatures actually exist. You're looking for a scientific explanation to something that cannot be explained with science.

The reason you can't predict what a Giant Eagle's NA should be is not that there is no pattern. Generally, bigger creatures in the Monster Manuals have thicker skin. However, it's that it is impossible to say what magically enlarging an eagle would do to its skin or feathers.

[Lord Vukodlak]

A guy in Full plate being more adept at not getting hit than a guy wearing regular clothes is pretty weird. Try and stab someone in regular clothes then try and stab someone in fullplate. If you hit the metal part... you missed him and hit the armor. D&D handles armor by having it negate attacks hit and miss are simply gameplay terms. If you miss then you failed to hit an area vulnerable to damage.

[Andezzar]

Try and stab someone in regular clothes then try and stab someone in fullplate. If you hit the metal part... you missed him and hit the armor. D&D handles armor by having it negate attacks hit and miss are simply gameplay terms. If you miss then you failed to hit an area vulnerable to damage.Yeah if you use gameplay terms this is true. But if you do that, natural or worn armor can reduce the effect of a hit (in common parlance). So it is not just DR that does that, which is what tuggyne claimed as far as I understood him.

Oh and the distinction between armor and wearer works well with worn armor, but not so much with natural armor.

[TuggyNE]

The problem with expecting Natural Armor to be predictable is that none of these creatures actually exist. You're looking for a scientific explanation to something that cannot be explained with science.

And that, of course, is why really strong-seeming mythical creatures often have really low Str scores. Oh wait, those actually make sense.

Hmm, OK, legendary creatures tend to have odd speeds that don't match expectations. Er, no, those mostly seem fine too.

Maybe it's that fictional beasts tend to have strange DR figures? No, not so much; only dragon DR is really off (and only in the sense that /magic is a bit lame).

Could it be that my expectations are being messed up by natural armor figures far more than almost any other stat? Why, bless me, that's what it is!

… yeahhh, I'm going to go ahead and say it: if there's not some internally-consistent, in-character rationale for stats, something is wrong. Even something so arbitrary as spell levels at least has a vague attempt at that; more powerful characters are better able to control magical energy, can control more and more potent quanta, and so on. And scholars in the setting can outline some sort of pattern to all this!


The reason you can't predict what a Giant Eagle's NA should be is not that there is no pattern. Generally, bigger creatures in the Monster Manuals have thicker skin. However, it's that it is impossible to say what magically enlarging an eagle would do to its skin or feathers.

See, I dislike unlabeled/lumped-in fudge factors like this: if there's some unusual effect that makes the eagle have better NA, label it! Nymphs have an ability that adds to AC, but I have no problems with it because its source is specified.

For that matter, if there was a generic pattern — say, if creatures matching certain criteria got double size modifier to NA upon size increases, certain other criteria only justified size modifier, yet others justified only half size modifier, and finally a few creatures got no increase to NA upon size increases, I'd consider it a lot more sensible. Maybe there is such a thing already, but I don't know what those criteria are, and I rather doubt it.


Yeah if you use gameplay terms this is true. But if you do that, natural or worn armor can reduce the effect of a hit (in common parlance). So it is not just DR that does that, which is what tuggyne claimed as far as I understood him.

No, Chronos basically explained the way I look at it. I'd somewhat prefer a system that took a different tack on armor, but D&D's assumptions basically square with that, and I'm not looking to completely change everything.