Since my polymorph meme has only garnered three downvotes so far I thought I’d offer a bit more controversial take, and see if I can manage to stir the pot a bit with this one.
Unfortunately:
- half of zero is still zero, and
- since one can’t go below 0HP there’s no HP pool to take health from.
As someone who had to DM more than I’d like, no dice, mate.
You’re still dealing damage, e.g. it could kill you from the massive damage rule if you dealt enough. Vampiric touch counts how much damage you deal, not how much hp the target loses.
I’d allow it, but instead of HP damage, you take as many levels of exhaustion.
Thats why you give exhaustion for revival without stabilisation.
I’d allow it, but instead of HP damage, you take as many levels of exhaustion.
since there is no negative HP you are doing no damage past 0. So even if the spell hits it does no damage since there is no damage left to do, half of 0 is 0.