Do things that interact with damage also interact with ability damage?
For example, if you have an attack that deals ability damage, such as an arrow created with Shadow Arrow (Champions of Ruin, p. 34), can you apply a damage bonus, such as from a +4 strength composite bow, to the ability damage?
Reason: I'm making an archer that stacks ranged damage bonuses and I'm wondering if it is a good idea to pick up an ability damage spell to complement his build.
Best Answer
In 3.5, Rules Compendium addressed this, saying that when you have an attack that deals ability damage (or negative levels), and would receive a bonus to its damage, the bonus damage is dealt as negative energy-based HP damage, not additional ability damage or negative levels.
So, for example, if you have 3d6 sneak attack damage and sneak attack with enervate, you deal 1d4 negative levels + 3d6 negative energy damage.
Note that bonuses to weapon damage never apply to spells. So inspire courage (“a +1 morale bonus on [...] weapon damage rolls”) doesn’t apply, but weirdly Weapon Specialization does because it says that it applies a bonus to “damage of the chosen weapon” and we have a special ruling saying that spells can be chosen as the “weapon”—if it said “weapon damage” of the chosen weapon, we might have a problem.
In researching this question for Pathfinder, I find a lot of people saying the same thing, but I cannot find any statements in the Pathfinder rules that indicate it. It seems that this is a rule that the Pathfinder community has ported (consciously or not) from 3.5 without Paizo’s assistance.