Is there a rule somewhere that states sneak attack damage is the same as that what delivered it? i.e. a flanker delivers a shocking grasp; sneak attack damage is also electrical.
If so, what happens if you sneak attack with multiple damage types? does it default to hp damage? does it default to weapon damage?
E.g. what happens if I sneak attack with a flaming short sword with poison that inflicts a base 4 hp piercing damage, 3 hp fire damage, and 3 points of temporary dex damage?
What happens if you sneak attack with only one source of non-hp damage, such as poison?
Any help pointing me in the right direction(s) would be appreciated.