It is a free action to cast Hellish Rebuke and a 1st level spell slot.
And then if it triggers (on taking damage), it is supposed to use a Reaction. But, if it is triggered during one of your own rounds from an incoming Attack of Opportunity, it consumes a full Action. It should be consuming your available Reaction, or not firing at all if the reaction is already used somehow (which is nearly impossible during your own round, since it is returned when your round begins). The second case normally only applies during enemy rounds, since you might have used a Reaction on other triggers.
It should never be wasting a full Action.
If it triggers correctly as a reaction during an enemy round, it doesn't seem to do any damage. Or maybe it missed. But it shouldn't miss.
Last edited by eventHandler; 09/10/20 01:10 AM.
