DR stacking

[doomman47]

So I have come across some abilities that give DR said DR also states that it stacks with DR provided by adamantine armor how do they work in conjunction? Like adamantine full plate gives dr3 and one of the abilities gives dr2 and the other gives dr3 would I get dr8 since both stack with adamantine?

[Adjoint]

No, unless the abilities stack with each other. If they don't the abilities give just DR 3 (higher of the two) that gets added to the DR of the armor with final reult DR 6.

[MrCharisma]

There are some abilities that specifically stack with others while others do not.

Some, like the STALWART feat stack with some abilities but not others.

If you can tell us which abilities you're using (preferably providing quotes and/or links) we can tell you whether they stack or not.

Without specifics, the general rule is that DR doesn't stack.

[doomman47]

fighter armor master and armored juggernaught

[MrCharisma]

RAW: no they don't stack.

You'd either get:

Adamantine DR + Armor Master DR
or
Adamantine DR + Armored Juggernaught DR.

So in this case it'd be DR:(3+2)- or DR:(3+3)-

It looks like Armor Master is better until level 11. There are trade-offs for both though, so it depends how much that 1 extra point of DR is worth to you

[doomman47]

What if an ability like the hero's hauberk was in play where it allowed adamantine to stack with other DR?

[Claxon]

The DR from Hero's Hauberk (+1) would stack with any other source, but wouldn't cause the sources to stack with each other if they didn't already.

DR from adamantine armor doesn't stack with other sources of DR (unless the other source says so).
DR from Armor Master stacks with adamantine armor, but not other sources.
DR from Armored Juggernaut stack with adamantine armor, but not other sources.

So you could have Hero's Hauberk + Adamantine Armor + either Armor Master or Armored Juggernaut.

[Slyme]

I was just thinking about something similar while looking at a couple classes that give different types of DR.

How would DR/slashing and DR/Adamantine interact with each other? Or DR/Slashing and DR/-?

For example, if you multi-classed say Oozemorph Shifter (Gives DR/Slashing at level 2+) and Invulnerable Rager Barbarian (Gives DR/- at level 2+)?

[MrCharisma]

Let's say you have DR:10/Slashing and DR:5/-

If you get hit by a bludgeoning/piercing weapon you get DR:10

If you get hit by a Slashing Weapon it bypasses the DR/Slashing, so you only get DR:5

They don't stack, but you get whichever is most beneficial at any time.

Next example:

Let's say you have DR:5/Bludgeoning and DR:5/Piercing

If you get hit by a Slashing weapon you get DR:5 (From either, but they don't stack).

If you get hit by a Bludgeoning weapon you lose your DR:5/Bludgeoning, but you still get your DR:5/Piercing, so you still get DR:5.

If you get hit by a Piercing weapon you lose your DR:5/Piercing, but you still get your DR:5/Bludgeoning, so you still get DR:5.

If you get hit by a Morningstar you lose your DR since it counts as Bludgeoning and Piercing, thus ignoring both your DR types.

EDIT: The same rules would apply for special materials, only the highest bonus counts, but a weapon would have to simultaneously get through all forms of DR to fully damage you. Also DR does nothing against acid/cold/fire/electricity damage, or any other type of damage that isn't caused by a weapon (I think Force damage ignores DR too, even if it's a weapon).

[Ryze Kuja]

MrCharisma is correct. The DR doesn't stack, it merely "overlaps" and you take the highest source of DR. For example if you have DR5/x and DR3/x from two sources, it doesn't become DR8/x, it should be DR5/x because it's your highest source.