Specifically, this question arose when I was running Twilight in the Duchy Verdorben and introduced the risen corpses. They have Perception=B1 and Mortal Wound=B11.
When describing how to fight the corpses, the scenario states:
In order to effect a rescue, the corpse must be slain outright – a weapon skill test that can deliver a B11 wound…
This makes sense for slaying the corpses, but couldn’t they be incapacitated by giving them a -1D wound and reducing their Perception to 0? (In this case it would need to be a B8 Midi wound since they have the Dead to Pain trait.)
I just wanted to make sure I wasn’t missing something here, since it’s so much easier to make a B8 wound than B11.
You are correct that monsters, just like other characters, are incapacitated when one or more of their stats are reduced to zero. However, those risen corpses should have the Infected by the Black Oil trait (page 22 of Twilight in the Duchy Verdorben).
Infected by the Black Oil confers the Brute and Thousand Yard Stare traits.
And the Brute trait (you’ll find it in the Codex), means the monster that has it does not count penalties to mental stats for the purposes of Incapacitation.
With their Speed B3 and the Dead to Pain trait, that means they need to take -4D in penalties to be incapacitated. A Traumatic wound (B10) would do it. But you could also do it with multiple midis or severes.
Technically, that would merely damage the corpse enough that it can no longer attack. Destroying it completely would still require a Mortal wound. You could do that by incapacitating it and then burning it though.