Brawler's Strangler archetype give you:
At 1st level, a strangler deals +1d6 sneak attack damage whenever she succeeds at a grapple check to damage or pin an opponent. The strangler is always considered flanking her target for the purpose of using this ability. This damage increases by +1d6 at 2nd, 8th and 15th levels.
Would Sneak Attack dice from another class stack with this application (dealing damage during a grapple)?
In case I'm being unclear, here's an example; if a 4th level character is a 1st level Brawler(Strangler) and 3rd level Rogue, how many sneak attack dice do they use when:
- flanking and hitting an enemy with a dagger?
- dealing damage with a grapple check?