Do ability modifiers from the same ability stack? For instance, can you add the same ability bonus on the same roll twice using two different effects that each add that same ability modifier? wrote:
No. An ability bonus, such as "Strength bonus", is considered to be the same source for the purpose of bonuses from the same source not stacking. However, you can still add, for instance “a deflection bonus equal to your Charisma modifier” and your Charisma modifier. For this purpose, however, the paladin's untyped "bonus equal to her Charisma bonus (if any) on all saving throws" from divine grace is considered to be the same as "Charisma bonus (if any)", and the same would be true for any other untyped "bonus equal to her [ability score] bonus" constructions.
Bob, Bob, Bob,
You seem convinced of your position beyond any doubt, but to me it appears that your position is merely one way to interpret the FAQ and I would interpret it differently. Do you have additional authority beyond the FAQ that you could cite?
Allow me to explain why I would argue that the FAQ you cite does not apply to this specific situation (Charm of Wisdom [Conversion Inquisition] Wis bonus to Bluff and Diplomacy stacking with Guileful Lore [Infiltrator Archetype] Wis bonus to Bluff, Diplomacy and Intimidate):
Read the descriptions of Guileful Lore and Monster Lore (which Guileful Lore replaces via the Infiltrator Archetype ability.
Guileful Lore (Ex): At 1st level, the infiltrator’s will is bent toward subterfuge and deception. She adds her Wisdom modifier on Bluff and Diplomacy skill checks in addition to the normal ability score modifiers. This ability replaces monster lore.
Monster Lore (Ex): The inquisitor adds her Wisdom modifier on Knowledge skill checks in addition to her Intelligence modifier, when making skill checks to identify the abilities and weaknesses of creatures.
Notice that Monster Lore specifically states that Wisdom is used in addition to Intelligence. However, Guileful Lore does not specifically state that Wisdom is used in addition to Charisma, but instead it states that Wis is used in addition to "the normal ability score modifiers." I would argue that this is intentionally a-specific to the ability score source with the intention of leaving it flexible.
Until or unless Paizo correctly the description of Guileful Lore to specifically state "Charisma modifier" or puts out an FAQ on this specific scenario, I would allow this. And if I did not allow a player to stack Guileful Lore and Charm of Wisdom, I would at least give them back Monster Lore.
Sidenote: As of this post, HeroLab, which is generally quite accurate with its Pathfinder character build rules, allows the stacking in this specific situation. I grant that it could be an oversight. But for now at least it is evidence that supports my interpretation.