I saw this question and was reminded of something that happened in one of my games recently: I, as a Life Cleric, used my Channel Divinity: Preserve Life feature on an ally who had been swallowed (It didn't affect the outcome significantly; I had two other possible plans that would probably have saved said ally).
But I'm curious. My ally had total cover, which prevented targetting her with a spell (say, Mass Cure Wounds, as in the linked question). But Preserve Life is not a spell. RAW, is this legal?
Best Answer
Yes, this works. (RAW)
Total cover specifies,
Channel Divinity: Preserve Life is neither an attack, nor a spell, so the only eligibility condition for targets is that a creature be
This is a obviously strict rules as written interpretation, and it relies on the principle that there are no secret rules, e.g. there is no secret rule that total cover prevents class features or racial abilities that are not attacks or spells from targeting the covered creature.