Armor as Damage Reduction Stacking Rules Clarification Needed.

[AbsolutGrndZer0]

I am using the Armor as Damage Reduction optional rule and a player is telling me I am doing it wrong in how it stacks.

So, pg 192 of Ultimate Combat says If a creature has magical armor, natural armor, and DR, it takes the best form of the special protection
provided by both its armor and its mix of DR and natural
armor to its DR/armor.

So, say you have a Lycanthrope with DR 10/silver. Then they get +4 natural armor, so that gives them 14/silver. Then say she wears a adamantite armor with a +2 armor bonus. Then being light is another +1 DR Does that then make her DR 17/-?

My friend insists that if you attack her with a silver weapon that deals 10 damage then the adamantite will stop 3, the natural armor bonus will protect from 4 damage and then the rest of the damage will blow through because it's a silver weapon.

I say that "best form of the special protection provided by both its armor and its mix of DR and natural" means it all stacks to 17/-

EDIT: Also, I know as the GM I can do what I want, but I wish to know the RAI/RAW so I can make an informed decision.

[agentJay]

Never heard of "armor as damage reduction optional rule", where is it located?

[Marthian]

agentJay wrote:

Never heard of "armor as damage reduction optional rule", where is it located?

I believe it is Ultimate Combat.

Edit: Armor As Damage Reduction

[iffbiff]

I would play it this way:

Since you are playing everything is DR instead of actual armor, then the DR 4 (from natural) and the DR 3 from the +2 adamantine would give DR 7/-. The fact of being a werewolf grants DR 10/silver. I would list the two side by side. The armor is on the outer layer, so anything hitting the werewolf has to go through the armor, therefore it takes 3 off of the top of everything. The natural armor also takes 4 off of the top of everything, for a combined total of 7. Whatever is left is then DR 10/silver. Ergo if that specific werewolf gets hit with a silver weapon, the first 7 points are eaten and then the remainder damages the werewolf accordingly, since silver bypasses the DR 10/Silver, but nothing bypasses the DR 7/-. An ethereal/incorporeal attack would bypass the armor and natural armor. Anything else is effectively DR 17/-.

[AbsolutGrndZer0]

I appreciate comments like "I would play it this way" but that doesn't help me, no offense meant. What I am wondering is what the RULES say in regard to the optional rule changes.

On a side note, my friend after re-reading the rules and thinking about it has started to realize he was thinking I meant something different than I did and that my interpretation is right, so while we now agree, I am still curious as to others opinions on what is RAW/RAI. If you don't agree with the RAW/RAI as you see it, feel free to say so! :)

I have emailed Jason Buhlman (Lead Designer) to see if he can tell me what the writer(s) intended since that's what I really want to know, but I am also asking here to get other opinions.

Part of the reason my friend and I clashed on this are we are both rules lawyers that have no problem with house rules. We just hate when a GM insists that the book says something it doesn't. Like if you want to say the sky in Golarion is hot pink with purple and blue clouds then that's your right as GM, but nowhere in the books does it say any such thing, so don't tell us it's in the book (and the "Golden Rule of RP" doesn't count, it allows you to change things in your game, it doesn't rewrite the book). :P

[Undermind]

Well, using the example in the SRD, the silver weapon would pass through 10 points of DR. They use a skelon in the example, wich has dr 5/bludgeon and dr 4/armor. In the example, the skeleton would subtract 9 damage from everything other can bludgeon, and 4 from bludgeoning weapons

[Fleshgrinder]

Okay, so, DR stacks weird with this system. it's more like having multiple forms of DR at the same time.

So first, you have "DR/Armor". This is the DR provided by your armor and what bypasses it depends on the armor itself.

Non magic armor is DR/magic

Magic armor provides DR/adamintine

Adamantine armor provides DR/-

So with your Lychanthrope, It would have 10/silver and DR 7/-

The weirder forms of DR, like silver or a specific damage type kind of act like seperate DR at the same time.

They stack, so a non-silver weapon will have its damage reduced by 17.

But a silver weapon would only be reduced by 7.

At least that is my understanding of the rules.

[Weirdo]

The RAW is very confusingly worded, but I think the majority interpretation is correct. Let me work my reasoning through here to avoid confusion:

SRD wrote:

DR/Armor: This type of DR blocks the damage of all attacks that would normally be affected by DR, based on the composition of the armor (see Table 5–1). Unlike most forms of damage reduction, DR/armor stacks with other types of DR.

This opening introduces DR/armor as a new mechanic separate from (but stackable with) other types of DR, which I'll call "innate DR."

SRD wrote:

For instance, when fighting a skeleton with DR 5/bludgeoning and DR 4/armor (+2 for armor, +2 for natural armor), the skeleton's DR/armor reduces 9 points of damage from non-bludgeoning attacks, and 4 damage from bludgeoning weapon attacks. Magic weapons and attacks from Large or larger creatures bypass the DR 4/armor, but not the DR 5/bludgeoning.

This is the skeleton example Undermine cited. RAW bludgeoning damage clearly bypasses the skeleton's innate DR/bludgeoning, but not its DR/armor. By analogy, silver would bypass your werewolf's innate DR/silver, but not its DR/armor.

SRD wrote:

Natural Armor Bonus and DR: Like a creature's armor bonus, a natural armor bonus is also converted into damage reduction. If a creature is wearing armor and has a natural armor bonus, the creature adds its armor bonus to its natural armor bonus to determine the amount of DR/armor that it has (see Table 5–2).

For instance, if a creature wearing a +2 chain shirt has DR 6/armor is then subject to a barkskin spell cast by a 6th-level druid (gaining a +3 natural armor bonus), its DR becomes DR 9/armor for the duration of the spell. This DR is bypassed by adamantine, or the attacks of Huge or larger creatures.

Table 5-2 shows the kind of DR/armor that natural armor gives according to whether that creature also has innate DR. Since your werewolf example has natural armor, but not DR/magic or greater, she gains DR 4/armor/magic from natural armor. This stacks with the adamantine armor's DR 3/armor/-, giving her DR 7/armor.

SRD wrote:

A creature that has both DR from a source other than armor and a natural armor bonus gains the effects of an enhanced form of DR, similar to how the composition of the armor grants special DR/armor defenses (see Table 5–1).

This line says that if a creature has DR in addition to their natural armor, the DR/armor granted by their natural armor is harder to bypass. It does not say anything about changing the way DR/armor stacks with the innate DR, as described by the skeleton example.

SRD wrote:

If a creature has magical armor, natural armor, and DR, it takes the best form of the special protection provided by both its armor and its mix of DR and natural armor to its DR/armor.

Sentence as parsed: best form of protection provided by (its armor) and (its mix of DR and natural armor) to (its DR/armor).

The "best form" rule applies only to calculating DR/armor, not innate DR. In this case, "mix of DR and natural armor" refers to the DR/armor granted by natural armor, which may be more difficult to bypass if the creature has innate DR. The "best form" rule does not change the way the DR/armor calculated in this manner stacks with innate DR, as described in the skeleton example above.

SRD wrote:

For instance, if a creature has natural armor and DR/magic and is wearing adamantine armor, that creature's DR/armor functions as DR/—, and can be bypassed by Gargantuan or larger creatures, since the adamantine armor provides the best of the two damage reductions.

So in the werewolf example, the wolf gets DR 7/armor/-, which stacks with innate DR 10/silver as long as no silver weapons are used, but does not stack with the innate DR/silver if silver weapons are used. (The creature's DR/armour functions as DR/-; its innate DR does not.)