Do "[Stat] to X" abilities really stack?

[Barbarian MD]

So I've seen a LOT of builds recently that combine classes and feats to gain [Stat] to X, and I'm wondering if they actually stack the way people say they do.

For instance, this is one I saw recently:

Using an Aptitude weapon or Weapon Aptitude

Legendary Warrior Dex to damage
Expert Throw to replace Str with Dex to damage.
Deadeye Shot for Dex to Damage.
Champion of Correlon for Dex to Damage.
Shadow Blade for Dex to Damage.
Fencing for Dex to damage.
Crossbow Sniper for 1/2 Dex to damage.
Hit and Run Fighter for Dex to damage.


And I've also seen where people combine a lot of different [Stat] to AC.
For instance, a build might have:

Shrewd Tactician - Int to AC
Monk - Wis to AC
Fist of the Forest - Con to AC
Arcane Duelist - Cha to AC


Do things like this ACTUALLY work?

[Thurbane]

It depends entirely on the wording of the ability, and what type of bonus it gives.

Bonuses of the same type (except dodge, and untyped) don't stack (unless a specific exception is called out).

[Barbarian MD]

Untyped don't stack? Ah, I think that does a lot of nerfing.

Totally misread you.

I think the biggest problem that I'm seeing crop up is that a lot of homebrew doesn't specify what type of bonus it is, and therefore a lot of people are exploiting that lack of definition.

[Darklady2831]

What Thurbane said.

Only the highest bonus of a certain type is applied, so if you had a feat that gave you an insight bonus to AC equal to your Int modifier, and one that gave an insight bonus equal to your Wis modifier, only the highest applies. But if the bonus from Wis was an enhancement bonus, they would stack.

[true_shinken]

What Turbane said.
That thing about Aptitude Weapon is just plain RAWtard anyway.

[Douglas]

Yes.

There are two things in general that prevent stacking. They are A) same bonus type, and B) same source of bonus. The first is easily eliminated from consideration by simply noting that most of these bonuses are untyped and the rest are generally a wide variety of different types. That leaves the second, which needs a slightly more thorough treatment.

Let's say you have a Nymph (http://www.d20srd.org/srd/monsters/nymph.htm) Paladin (http://www.d20srd.org/srd/classes/paladin.htm) with at least 2 levels in the class. She gets charisma to saves for being a Nymph and again for being a level 2+ Paladin. Both bonuses are untyped, so the only general rule that could prevent stacking is the same source prohibition.

Now here's the point where a lot of people say "aha, the source is charisma for both!" These people are wrong. The source of one is the ability Unearthly Grace, and the source of the other is the ability Divine Grace. The fact that they both use charisma to determine the magnitude of their bonus is irrelevant. However similar their effects may be, these are two distinct separate abilities. If you found another class that gives Divine Grace it would be the same ability as Paladin and would therefore not stack*, but these particular two abilities are different and do stack.

* This is actually a significant hurdle for stacking saves - a very large portion of the classes with X-stat-to-saves abilities give Divine Grace specifically.

[Barbarian MD]

So, does a Monk/Swordsage get x2 Wis to AC?

[erikun]

I believe that Fist of the Forest is specifically a Natural Armor bonus, which means that it does stack with the Monk's AC bonus. It does not, however, stack with the Amulet of Natural Armor.

I have seen a lot of people attempt to stack Monk AC with AC from other sources, with varying results. Most other attempts at ability-stacking tend to fail, given that a lot of them explicitly do not stack. (There are a lot of bonuses to saving throws "as the Paladin's ability", meaning that they don't work together.)

I'm afraid I can't check your specific examples, as I'm not familiar with all the feats/abilities.

Homebrew is generally not considered as part of build analyses, because homebrew can (literally) be anything of any power level. It would probably be best to consider any homebrew bonuses to be equilivant to the common class bonuses of the same type, meaning they wouldn't stack.

[EDIT]

So, does a Monk/Swordsage get x2 Wis to AC?
I believe that the unarmed Swordsage explicitly states that it grants the same bonus as the Monk ability, or that it explicitly doesn't stack with the Monk's bonus to AC. I'm away-from-book and so cannot confirm, though.

[Greenish]

So, does a Monk/Swordsage get x2 Wis to AC?By RAW, no, but that's not because of stacking rules, but because you can't qualify for both bonuses at the same time.

If you could, I don't think they'd stack, since they both come from a class feature called "AC bonus".

[Edit]:
I believe that Fist of the Forest is specifically a Natural Armor bonus, which means that it does stack with the Monk's AC bonus.It's not natural armour bonus.

Both monk and FotF class features are "AC bonus (Ex)", and the one from FotF says "see the monk class feature".

[Douglas]

So, does a Monk/Swordsage get x2 Wis to AC?
No, for two reasons:
1) The ability in both cases is "AC Bonus". This means they are the "same" ability (even though they actually do have slightly different mechanics) and therefore do not stack.
2) Swordsage AC Bonus works only in light armor. By strict RAW, it does not work in no armor. In order to satisfy the requirements of both abilities you would have to wear both light armor and no armor simultaneously, which is obviously not possible. Yes, this is obviously not RAI (really, take your armor off and suddenly you can't dodge any more? huh?), but there it is.

[tuesdayscoming]

So, does a Monk/Swordsage get x2 Wis to AC?

Can't remember if it explicitly says anything about stacking in either entry, but there would be another issue here. Monks only get the bonus while unarmored, and Swordsages only get it while in light armor (and not while unarmored, RAW).

edit: Ninja'd