Natural Armor Stacking

[thecrimsondawn]

I remember that nat armor almost never stacks since it itself is a bonus type, but I know that in some cases it does. I however do not remember what does and does not stack with it.

Does anyone know the ruling on what nat AC stacks and what does not? Ive got so many sources of nat AC to worry about that its giving me a bit of a headache.

[Khedrac]

If two things state that they grant bonus natural armor then one uses the higher value.

However, if something states that it grants a type bonus to natural armor it will add to something that grants natural armor.

For example, the barkskin spell grants an enhancement bonus to natural armor and not natural armor and thus it stacks with actual natural armor.

What it won't stack with is another enhancement bonus to natural armor - such as an amulet of natural armor (which also grants a bonus to natural armor).

[grarrrg]

Natural Armor only ever stacks if the ability specifically says it stacks.

Improved Natural Armor feat (http://www.d20srd.org/srd/monsterFeats.htm)
"The creature’s natural armor bonus increases by 1."

Dragon Disciple (http://www.d20srd.org/srd/prestigeClasses/dragonDisciple.htm)
"gains an increase to the character’s existing natural armor (if any)"

If it does not 'increase existing', or say 'stacks with', then it does not.