I just tested how Guerilla, Sneaking, and Invisibility stack with Backstabs.
Weapon: 35-58 Piercing damage poinard Target: Charred Bone Idol (perhaps not the best target)
All attacks were backstabs.
From behind, no sneaking: 40 * 2 (Absorbed: 8?) From behind, while invisible, no sneaking: 48 * 2 (Absorbed: 8?) From behind, while sneaking: 140 * 2 (Absorbed: 30) From behind, while sneaking, while invisible: 150 * 2 (Absorbed: 30)
I'll do some more tests, hopefully finding a squishier target.