Let's say I have DR 5/- and a buddy casts Stoneskin on me for DR 10/Adamantine. Can these separate sources of DR stack? If so, how does it work?
Also, does this same principle work for Resistances (I.e. Deathless Spirit Racial Trait and Deathless Armor Property)?
DR always overlaps unless you have a source that specifically states it stacks with other DR. Those don't say such a thing, so they overlap (no stacking).
If you get attacked by something with no way to bypass your DR, then you have the highest one: DR 10. If the enemy has an adamantine attack, then it bypasses the DR 10 but not the DR 5, so you only get DR 5.
There will never be a time where this character would get DR 15 from those two sources.
