[RPG] Should I just assume that a Warlock with the Fiendish Vigor invocation starts every combat with 8 temporary hp


Warlocks have access to this invocation:

Fiendish Vigor

You can cast false life on yourself at will as a
1st-level spell, without expending a spell slot or
material components.

False Life is a 1 action spell with a 1 hour duration that does this:

Bolstering yourself with a necromantic facsimile of life,
you gain 1d4 + 4 temporary hit points for the duration.

Given the negligible cost in casting it (outside combat), wouldn't every warlock just keep casting it round after round until they got 8 temporary hp which would then last 1 hour? And then do it again when those expired. And again. And …

Best Answer

Sure, it can't hurt.

Assuming that the player agrees (and I see no reason for them not to), yes, you can just assume that a warlock with that invocation starts with their buffs on.

I played a 3.5 game where all of us were using highly optimized, self-buffing characters who would stack buffs on ourselves before every combat. It was a waste of time for everyone to announce their buffs at every encounter, so the DM just assumed that we had them on at the start of each non-surprise encounter, and we subtracted the resources ourselves. We never had any issues with this system.

Just don't forget about it--having a spell constantly on like that means that they will show up on detect magic, for example, and there might be situations where constant obvious spellcasting might draw unwanted attention.