Let's assume a good cleric tries to heal a hurt Dhampir, not knowing they are a Dhampir or not knowing about their "Negative Energy Affinity". So they Channel positive energy or use e.g. Cure Light Wounds. What happens:
- Dhampir is healed
- Nothing
- Dhampir takes damage (but gets a saving throw)
Also, if the Dhampir is not healed, would the cleric notice that it didn't work as expected?
The reason I'm asking is that according to the Channel Energy description a cleric has to choose whether to heal or damage undead, they can't do both:
A good cleric (or one who worships a good deity) channels positive energy and can choose to deal damage to undead creatures or to heal living creatures.
But cure light wounds says it heals living creatures and damages undead. But I remember reading another description of cure light wounds that said you can choose whether to heal or harm (like you do with Channel Energy). Maybe that was from a or DnD edition?
Best Answer
The dhampir racial trait negative energy affinity says that "a dhampir reacts to positive and negative energy as if it were undead—positive energy harms it, while negative energy heals it." The spell cure light wounds uses positive energy to heal, so the dhampir would be harmed by the spell.
However, a cleric that employs the supernatural ability channel energy to heal living creatures leaves the dhampir unharmed by the ability. When used to heal living creatures, that positive energy has no effect on undead creatures including ersatz ones like the dhampir. Were the cleric to use instead the ability channel energy to harm undead creatures, the dhampir would be harmed as would any undead creature, again, including ersatz ones like itself.
Whether a cleric realizes the dhampir is harmed or unaffected by either effect will depend on how such effects function in the campaign and, probably, the severity and obviousness of the dhampir's wounds. That's something that should be discussed with the GM or realized over the course of a campaign.