natural armor stacking

[Piccolo]

Do different sources of natural armor stack? Say I have a Tiefling Barbarian with the Armor of the Pit (+2 natural armor) feat, and he buys an Amulet of Natural Armor. Do they stack? What if the Barb gets natural armor from a rage power (Beast Totem from the APG), does that stack?

[Bob Bob Bob]

So this is dependent on the actual wording. There's actually two different ways to add natural armor. One is "natural armor bonus" which is a flat number that overlaps (does not stack) with any other "natural armor bonus". This is Armor of the Pit, Polymorph spells, and Beast Totem. The second is "enhancement bonus to natural armor" which increases the natural armor bonus (things without a natural armor bonus actually have a natural armor bonus of +0). This is an Amulet of Natural Armor or the Barkskin spell and it doesn't stack with any other enhancement bonus to natural armor.

So you can have both a "natural armor bonus" and "enhancement bonus to natural armor" but unless the feat/class ability/spell/whatever says otherwise you only get the best value for those two and other values are ignored.

[Piccolo]

So, you are saying Armor of the Pit doesn't stack with Beast Totem? Or did I get that wrong?

[bigrig107]

That is correct. They don't stack.

If Beast Totem said "creature gains a bonus to their existing natural armor..." it'd stack.

That's how a lot of monster templates are worded.

[Gisher]

Correct. Armor of the Pit and the NA Bonus from the Beast Totem rage power do not stack with each other because they are both natural armor bonuses. An Amulet of Natural Armor would stack with either of those because it provides an enhancement bonus to natural armor.

[Zwordsman]

a specific example of it stacking is the wording on Dragon Disciple's nat armour bonus. it calls out stacking with a specific thing

[Claxon]

Yeah, it looks like this is covered but the whole thing depends on specific wording.

Natural armor bonus vs enhancement bonus to natural armor

Bonuses of the same type do not stack. So as mentioned pit fiend armor and beast totem's bonuses do not stack because they are both the same type of bonus. Natural armor bonus.

But a amulet of natural armor provides an enhancement bonus to natural armor (and creatures without any are treated as having +0 natural armor). This would stack with either pit fiend armor or beast totem. However it doesn't stack with Barkskin which is also a enhancement bonus to natural armor.

[fretgod99]

Zwordsman wrote:

a specific example of it stacking is the wording on Dragon Disciple's nat armour bonus. it calls out stacking with a specific thing

To be pedantic, Dragon Disciple's natural armor increase specifically states that it stacks with itself. The reason it works with other natural armor bonuses is because the Dragon Disciple class feature is a natural armor bonus increase. It doesn't provide a natural armor bonus; it increases the existing natural armor bonus.