Slashing Grace, Identical Class Abilities, and Dex Damage

[Meirril]

So this is an ability stacking question. Slashing Grace, Unchained Rogue's Finesse, and the Swordlord all give an ability to use Dex instead of Str to determine weapon damage. Two of them are class abilities, and 1 is a feat. Normally abilities from different sources stack, but these are all substitution abilities, right? None of them outright say you add dex mod to damage, right?

So...does anyone think you get dex mod to damage more than once? If you do think so, would 2 different class abilities stack? In other words, would a Unchained Rogue 3, Swordlord 1 with Slashing Grace get dex mod to damage x1, x2 or x3? Please give reasons for your answer!

Seperate question: Do class abilities that essentially give the same flat bonus (without introducing a type) stack?

[LordKailas]

This came up recently and according to this FAQ apparently the answer is no.

I agree it seems like they should since they're different abilities and therefore seem to be different sources.

Edit: I missed your second question. They should stack as per what it says about untyped bonuses.

Bonuses wrote:

Bonuses without a type always stack, unless they are from the same source.

[Meirril]

Ah, thanks. That FAQ solves a lot of problems.