I recently was encrusting some stuff, and after putting a few "Rocky Crusts" on a weapon the weapon was suddenly listed as dealing NEGATIVE piercing damage. I exited out of the game, reloaded and tried the same encrust on a different weapon; it lowered that weapon's piercing damage. No damage decrease is listed as part of the Rocky Crust encrust, and I'm pretty sure that weapons aren't supposed to deal negative damage in any case. Something is definitely wrong here.
No, that's intended. It just doesn't show up because no item will ever display negative damage values, and the encrust stats are (presumably) the stats as they would appear when crusted onto an item with no base stats. I mean, what does -3 slashing damage on a weapon even mean? Nothing, that's what. But it will reduce existing slashing damage. ((Also, you just glued a bunch of rocks to your weapon. Did you really expect it to be as sharp as it used to be?)) EDIT: reread your description, and I missed you saying that apparently it can show negative piercing damage? So that's odd.
Well, even if it is supposed to reduce slashing and piercing the fact that it doesn't display this fact is still a MAJOR flaw in the interface. Yes, and even if the other part doesn't count this definitely is a bug.
