Our gaming group has decided to give this system a try, but I'm having trouble wrapping my brain around one specific section of it pertaining to natural armor.
According to the variant rule:
A creature that has both DR from a source other than armor and a natural armor bonus gains the effects of an enhanced form of DR, similar to how the composition of the armor grants special DR/armor defenses (see Table: Armor Composition and DR). If a creature has magical armor, natural armor, and DR, it takes the best form of the special protection provided by both its armor and its mix of DR and natural armor to its DR/armor. For instance, if a creature has natural armor and DR/magic and is wearing adamantine armor, that creature’s DR/armor functions as DR/—, and can be bypassed by Gargantuan or larger creatures, since the adamantine armor provides the best of the two damage reductions.
How is it determined what the 'best form' of damage reduction is? I understand that DR/- is the best (excepting DR/epic if running a mythic game), but the example doesn't address other forms, like DR/Bludgeoning, or DR/Chaotic, or DR/Silver. What is the hierarchy involved? Which of those is better than the other?
I would assume this is basically the revers of the 'Overcoming DR' heirarchy in the glossary of the Core rule book where higher magic bonuses can beat out better DRs:
DR Type | Weapon Enhancement Bonus Equivalent
cold iron/silver | +3
adamantine* | +4
alignment-based | +5
So adding 'magic' and 'weapon type' DRs would make the overall DR line look like this:
weapon-type(B/S/P) < Magic (+1) < Cold Iron/Silver < Adamantine < Alignment-based < Epic < DR/-