Is there a rule that states sneak attack damage can't be applied more than once per attack? There are several instances of feats and weapon enchants that allow rogues to gain the sneak attack damage even if they have already gotten it this turn, but nothing specifically talking about if one attack can apply multiple instances of it. Any insight into whether or not the following works the way I think it does would be greatly appreciated.
- Rogue uses Knockout from stealth, which gains sneak attack damage.
- Rogue uses an action point, triggering the Slaying Action feat.
Slaying Action: Benefit: If you spend an action point to take an extra action and have already dealt Sneak Attack damage during this round, you can deal the extra damage a second time during this turn.
- Rogue performs a Coup De Grace against the now helpless target, scoring an automatic critical hit with sneak attack damage from slaying action. This critical hit triggers the Wraithblade enchant.
Wraithblade: Critical: +1d6 damage per plus, and if you have the sneak attack class feature (whether granted by class or multiclass feat) you may apply your bonus sneak attack damage even if you have already done so this round or this encounter. Gaining sneak attack damage in this way does not count toward its use restriction.
Does the Coup De Grace gain the benefit of two sneak attacks? Would both be auto-maximized, or would Wraithblade be a straight roll? Or is it not legal to gain this bonus twice on one attack?