D&D 5E Bonus action spell and reaction on your same turn

[Ancalagon]

Hello

This rather specific edge case happened last night:

The warlock backed away from a foe, triggering an AOO. Their plan was to back away, cast hex (a bonus action) then eldrich blast (a cantrip). But they got hit, which triggered hellish rebuke (a non-cantrip reaction spell). Can they still cast hex?

 

[Lyxen]

Theoretically no, see here. The limitation is during your turn, which is unfortunate if you use your reaction to cast a non-cantrip spell during your turn.

 

[billd91]

The warlock backed away from a foe, triggering an AOO. Their plan was to back away, cast hex (a bonus action) then eldrich blast (a cantrip). But they got hit, which triggered hellish rebuke (a non-cantrip reaction spell). Can they still cast hex?

By the rules, no. Within that context, if you feel the hex/eldritch blast combo is your priority, then opt not to take the hellish rebuke reaction - it's your choice. Or, if you take the hellish rebuke reaction, then just fire off the eldritch blast and use the hex next round.

With all that said, since reaction spells are castable outside of your turn entirely with their own special action economy account, I don't think it's necessarily problematic to take them outside the normal accounting of spellcasting actions in your turn. If the enemy had hit you on his turn, you'd have gotten that hellish rebuke, then the hex, and the eldritch blast on your turn and all of the action economy accounting would have been satisfied. It's not that abusive to allow it all on your turn proper.

 

[Umbran]

It's not that abusive to allow it all on your turn proper.

The problem may not lie in this particular combination, but in precedent of allowing a spellcaster to get three spells off in the same round, especially if the player finds a set of spells that makes use of some synchronicity we haven't considered because you nomally can't do that.

 

[Ancalagon]

The problem may not lie in this particular combination, but in precedent of allowing a spellcaster to get three spells off in the same round, especially if the player finds a set of spells that makes use of some synchronicity we haven't considered because you nomally can't do that.

It's what I've been thinking about.

(Now before we begin, a spellcaster absolutely can have 3 spells go off in a round. Had the warlock been away from the zombie, cast hex and blasted it, then the zombie moved it on its turn, attack the warlock, the warlock fiendish rebukes, that's 3 spells in a round and it's perfectly ok by the rules. It's 3 spells in a turn that is the issue.)

The "no bonus spell + action spell" is a way to limit spellcaster's "volume" - how many spells they can cast at once. It would be trivial to do "bonus spell + normal spell" all the time.

You can do it with an action surge (because that's an exception), and this is not trivial - you have to spend a resource that you can't get again until you short rest, and you have had to take the fighter class to boot to get the ability.

So the question is, can you trivially trigger a reaction on your turn so you can weaponize it? Sure you can move up to an enemy and back away, but the enemy has 1: to hit you, 2: if it hits you, you are taking damage, 3: the enemy has to decide to attack you - they may already have spent their reaction, or may decide they don't like what you are selling.

 

[doctorbadwolf]

RAW aside, there really isn't any practical reason to disallow it.

 

[Lyxen]

RAW aside, there really isn't any practical reason to disallow it.

Except if you consider that, in addition to the balance of avoiding multiple leveled spells in the same "instant", the rule is also there for "verisimilitude" and to avoid a character seemingly casting three spells in a flash, if he could do that at that point in time, why not all the time ?

 

[doctorbadwolf]

Except if you consider that, in addition to the balance of avoiding multiple leveled spells in the same "instant", the rule is also there for "verisimilitude" and to avoid a character seemingly casting three spells in a flash, if he could do that at that point in time, why not all the time ?

both spells are basically instant cast spells. I don't really understand what is prompting your question/objection.

What stops Hex and Hellish Rebuke being cast very quickly together, mere seconds apart at most, is simply that Hellish Rebuke can only be cast when the caster takes damage. There is nothing weird about a reflexive action happening at basically the same time as a very quick and easy conscious action. Real people do that, all the time. Hellish Rebuke is arcane muscle memory.

 

[Umbran]

Hellish Rebuke is arcane muscle memory.

The exact same argument holds for every reaction spell, though.

I suspect that the meat of the point of the restriction isn't so much in the casting time as it is in the restriction to cantrips - which can't be upcast. "Single action cantrip" only eliminates two combat action cantrips - Magic Stone and Shillelagh.

So, you can't move, get hit by an AoO that has an energy component, upcast Absorb Elements (reaction) and then Shilllelagh (bonus, cantrip), and beat the ever-loving crumbs out of someone with the stored energy all on the same round.

 

[doctorbadwolf]

The exact same argument holds for every reaction spell, though.

Exactly.

I suspect that the meat of the point of the restriction isn't so much in the casting time as it is in the restriction to cantrips - which can't be upcast. "Single action cantrip" only eliminates two combat action cantrips - Magic Stone and Shillelagh.

So, you can't move, get hit by an AoO that has an energy component, upcast Absorb Elements (reaction) and then Shilllelagh (bonus, cantrip), and beat the ever-loving crumbs out of someone with the stored energy all on the same round.

Sure, maybe. Which you still can't do if you allow reaction spells to not count for the restriction.