I was looking at Deadly stroke, which doubles the normal damage for an attack. Will this also double the precision damage from the Swashbuckler's precise strike deed?
It wouldn't be. As far as I know, Precision damage is never multiplied by anything.
It is a game of semantics, I know, but it says it doubles the normal damage, not multiplying... I'm really not sure how to rule on this...
Doubling is multiplying, and no, it wouldn't be multiplied as extra damage dice over what a weapon normally deals are never multiplied.
Deadly Stroke doubles damage. "Double damage" is a well-defined term. Bonus damage in the form of a flat number, like Precise Strike, is doubled.
There is an inconsistency in the core rulebook (first printing, which is what I have access to), in that the general rules for double damage only say that additional damage dice (like sneak attack) are not doubled, but critical hits say that precision damage is not doubled.
Deadly Stroke doubles damage. "Double damage" is a well-defined term. Bonus damage in the form of a flat number, like Precise Strike, is doubled.
There is an inconsistency in the core rulebook (first printing, which is what I have access to), in that the general rules for double damage only say that additional damage dice (like sneak attack) are not doubled, but critical hits say that precision damage is not doubled.
A further reading taught me that critical hits don't double precision damage; it's even mentioned in Precise Strike. But other damage-doublers do.