Originally Posted by Huyt
You are forgetting about the guerilla talent which give a x2 damage when sneaking (sneaking cost 1AP when it's level 5).
So you can multiply your calculation by 2 smile

Also there is a trait i think that increase backstab damage by 20%.

The trait is 20% increase of chance to hit, not damages.

There's a characteristic that makes sneaking as fast than walk/run without sneaking, I didn't tried it but wonder if it has any effects in combats.