[JCurwen3]

The way I read Supernatural Durability is that you can keep hacking at the guy, but unless you use that "one specific item" (and / or something to which they have a Vulnerability), or do one single blow that does 10 x HP at once, the guy's still alive.

Technically, does this mean he can get into unlimited negative HP, like -100 x HP, or even -10M x HP? Or should it just be capped somewhere (like -10 x HP)?

Normally -10 x HP represents destruction of the body; what is the state of the supernaturally durable character at such high negative HP?

Other than the last question (the state of the body), which I normally waive away as "it's Supernatural" but can't honestly answer, I'm fairly certain I understand it as yes, you can get into unlimited negative HP, and it isn't capped.

This was all sparked by a debate I had with one of my players about the advantage - just intellectual curiosity / looking for a tie-breaker, as it isn't relevant to our game and I don't generally allow the advantage even for my own NPCs.