So question. When using form of the dragonwe'll say level three it reads.
"This spell functions as form of the dragon II save that it also allows you to take the form of a Huge chromatic or metallic dragon. You gain the following abilities: a +10 size bonus to Strength, a +8 size bonus to Constitution, a +8 natural armor bonus,"
My simple question. How dose it affect creatures who are perhaps smaller or larger then medium? I assume you'd always become huge size but would the effects be lesser or greater depending on your base size.
Second side question is, dose natural armor stack. If you have innate natural armor dose it simply stack with it?
As per the polymorph rules, you are first reduced down to Medium or grown to Small (with stat modifiers in the [Polymorph] description), then you apply the effects of the polymorph spell. So no, large, huge, gargantuan or Diminutive creatures all become the same size.
The new natural armor bonus doesn't stack with the old. Also, your old Natural Armor bonus is probably an attribute specific to your form, and therefore lost when you polymorph. But if you have an active Amulet of Natural Armor, it works just fine.
If it says you become a Huge dragon, you become a Huge dragon regardless of what your original size.
Natural armor bonuses do not stack. If you have natural armor from your race, you lose this bonus when you polymorph. However, Amulet of Natural Armor would still work on your polymorph since the item explicitly increases your existing natural armor bonus.
If a polymorph spell is cast on a creature that is smaller than Small or larger than Medium, first adjust its ability scores to one of these two sizes using the following table before applying the bonuses granted by the polymorph spell.
Clink link for table because it's hard to format.
