FIendish vigor

[Darkbru]

If I choose fiendish vigor as as an Eldrich Invocation so I have to have false life as one of my prepared spells? Or do I get it in addition and it doesn’t count agains the number of spells known?

[Hesh]

It is not a Known Spell, nor is it added to your spell list.

Nor do warlocks prepare spells.

[Darkbru]

It is not a Known Spell, nor is it added to your spell list.

Nor do warlocks prepare spells.

Okay. So I’m understanding it as I can just cast that spell for free whenever I want and it doesn’t count against my known spells.

Sorry, I’m just new to D&D.

[KorvinStarmast]

So I’m understanding it as I can just cast that spell for free whenever I want and it doesn’t count against my known spells.
That is correct.

[Grod_The_Giant]

Okay. So I’m understanding it as I can just cast that spell for free whenever I want and it doesn’t count against my known spells.

Sorry, I’m just new to D&D.
Yup! Remember to cast it a couple times in a row until you roll the maximum number of temp HP.

[Greywander]

Yup! Remember to cast it a couple times in a row until you roll the maximum number of temp HP.
I would ask your DM if you can just skip rolling entirely and automatically get the maximum number of hit points, provided that you have a minute or so to repeatedly cast the spell. Obviously, if you're in combat or are otherwise time constrained, you'd have to roll for it, but if you have plenty of time then why not streamline the process?

[Vogie]

If you have the invocation, you can cast it only at first level, period. It's not a known spell for you to cast with a spell slot. Raven Queen and Undying warlocks can also choose it as a spell that's known to them, can cast it using a spell slot, which scales with that spell slot's level.

A 7th Level Undying Warlock, for example, can cast False Life using one of their spell slots - but it would be at 4th level, thus providing 1d4+4+20 Temporary Hit points (THP).

Note that Temporary HP doesn't stack, so you cannot, for example, have 8 THP from Fiendish Vigor, then use a spell slot for Armor of Agathys (AoA) for an additional pile of THP (5 THP per slot level) - the THP from AoA would overwrite the False Life HP. In the same way, while you CAN* cast AoA then false life with Fiendish Vigor, it's a terrible idea, as you would lose 100% of the effect of AoA.