Does Binder's Pact Augmentation DR/— stack with DR/— Gained From a Vestige?

Question

I am wondering if the damage reduction/— granted by a Binder's Pact Augmentation class feature stacks with the Vestige's Arete damage reduction/—.

Arete

Damage Reduction: Your body becomes unnaturally tough as you gain damage reduction 5/—.

Pact Augmentation

Pact Augmentation (Su): Beginning at 2nd level, you can draw additional power from the vestiges you bind. As long as you are bound to at least one vestige, you can choose one ability from the following list. Each time you rebind a vestige, you also reselect your pact augmentation ability.

As you attain higher levels, you can make additional selections from the list. You gain one additional ability at 5th, 10th, 16th, and 20th level (to a maximum of five selections at 20th level). You can choose a single ability multiple times, and their effects stack. For instance, at 16th level you could choose bonus hit points twice and damage reduction twice, gaining +10 hit points and damage reduction 2/—.

Answer 1

Strictly, no, but that could quite possibly be an oversight

Arete was written for the Mind’s Eye web supplement, not a published book. Mind’s Eye has a pretty good track record as far as this goes (and the published books don’t have as good a track record as one might hope), but there’s still something to be said here. That particular episode of Mind’s Eye is notorious for giving Binders not nearly enough power points to actually use those Powers particularly well for the day, at the level they’re gotten.

The Damage Reduction ability given by Arete is a reference, of sorts, to the racial Resilience ability of Elans, which is not actually Damage Reduciton (and would stack with the Pact Augmentation ability). Moreover, Arete’s Damage Reduction is equal in value to what Pact Augmentation would give you if you chose it all 5 times at 20th level. DR 10/– is not exactly earth-shattering here, particularly since Binder 20 is pretty much strictly inferior to Binder 15/Knight of the Sacred Seal 5. And, notably, the Pact Augmentation ability specifically says it stacks with itself. As you note, by the fluff it is supposed to be extracting more power from the Vestige itself; it certainly makes sense that you could Augment a Pact with a DR-granting Vestige to get more DR.

So while okeefe is totally accurate in terms of how the rules work, there may be a case for your DM to allow it. I would, for whatever that’s worth.

Answer 2

No. The damage reduction from two different sources do not stack.

Damage Reduction, d20srd

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.