Hello,
I was wondering if the DR from an adamantine breastplate would stack with the Invulnerable Rager Barbarian archetype. Does anybody out there know for sure?
It does not. Only the greatest source of DR against a given attack applies, unless the sources explicitly stack, such as the Barbarian rage power Improved Damage Reduction.
How do you know this?
Some magic creatures have the supernatural ability to instantly heal damage from weapons or ignore blows altogether as though they were invulnerable.
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If a creature has damage reduction from more than one source, the two forms of damage reduction do not stack. Instead, the creature gets the benefit of the best damage reduction in a given situation.
