Shield Mastery and Overcoming DR

I looked through a few other Shield Master threads but they had mostly devolved into fighting and bickering. Please don't argue over my assumptions until at least we come to a consensus on my question lol.

The assumptions for this thread are:

• A shield can have a +10 weapon enchantment mod and a +10 shield enchantment mod, paying the respective weapon/shield costs.
  
• If it comes up, Shield Mastery means you can dual wield shields at no TWF penalty.
  
• Spiked + Bashing Heavy Shield is 2d6 even though developers have said it wasn't their intention (my DM might change it to 1d10, but that's not the point of this thread).
  

Say you have a +1 Keen Defending/+5 Bashing Spiked Heavy Shield. Would the +5 from Shield Mastery that applies to the weapon mod overcome DR, or does it only affect attack and damage? I don't know if the "as if" clause means it only applies to attack and damage, or if it also applies to overcoming DR. Here's the quote with relevant portions bolded:

Benefit: You do not suffer any penalties on attack rolls made with a shield while you are wielding another weapon. Add your shield's enhancement bonus to attacks and damage rolls made with the shield as if it was a weapon enhancement bonus.

Shield Master (Combat)

Your mastery of the shield allows you to fight with it without hindrance.

Prerequisites: Improved Shield Bash, Shield Proficiency, Shield Slam, Two-Weapon Fighting, base attack bonus +11.

Benefit: You do not suffer any penalties on attack rolls made with a shield while you are wielding another weapon. Add your shield's enhancement bonus to attacks and damage rolls made with the shield [i]as if it was[i] a weapon enhancement bonus.

It specifically calls out attack and damage rolls. And it says as if it were an enhancement bonus.

Reading it, it makes me think Shield Master does not apply to bypass DR. Though I'm not sure what the intention was.

Also, none of your assumptions actually matter for the quesiton.

I think it would, It's part of the damage roll, whether it's able to bypass the DR. The as if should make it work just like the magic weapon.

Magic weapons have enhancement bonuses ranging from +1 to +5. They apply these bonuses to both attack and damage rolls when used in combat. All magic weapons are also masterwork weapons, but their masterwork bonuses on attack rolls do not stack with their enhancement bonuses on attack rolls.

SO it's the same wording, bonus to attack and damage rolls. So it'd work with the DR too.

as if it was a weapon enhancement bonus.

You got yourself some bypassing DR action.

Claxon, I didn't really know what was pertinent, and it was in case someone wanted to show an example or whatever. But you're right, it didn't really have much to do with it.

So far it's 2 to 1 for overcoming DR. I can see both ways, leaning slightly toward overcoming DR, but I might just be biased because I'd like it to work that way lol. I just don't know for sure whether overcoming DR is part of attack and damage rolls.

I do like the magic weapons quote though, Chess. Has the same wording. "apply these bonuses to both attack and damage rolls" vs. "enhancement bonus to attacks and damage rolls".

Also, interesting Valley girl quote Human Fighter.

EDIT: Damage reduction isn't part of the damage roll technically. Damage reduction is a property of what's being attacked. Don't know if that's relevant.

Bypassing might be considered as part of the damage roll.

Weapons with an enhancement bonus of +3 or greater can ignore some types of damage reduction

DR Type Weapon Enhancement Bonus Equivalent
Cold iron / silver +3
Adamantine* +4
Alignment-based +5

and since it's counting as if it was a weapon then it counts. I don't see anything in any wording that wouldn't let it count.

Chess, might want to just edit your last comment since it's less than an hour old lol.

That does give credence to it overcoming DR. I'm getting more convinced of it.