D&D 5E Warcaster Feat + Dissonant Whispers

[Riley37]

It is a common, if not universal, ruling, that when you cast Dissonant Whispers at someone, and they fail their save, and they have an available Reaction, they *immediately* use that Reaction to turn and run away, which means that if they were engaged in melee with you, they're not Disengaging and they provoke an opportunity attack as they flee in terror. (Momentary terror; they do not gain the Frightened condition.)

Warcaster allows the use of an offensive spell as an Opportunity Attack, single target, converting its casting time from 1 Action to your Reaction.

Therefore, if you have Dissonant, check out Warcaster, and vice versa. If you have Dissonant and not Warcaster, then you can opportunistically stab them as they run, or whatever; that's already fun. The combination of 3d6 Psychic, plus making them disengage so you can cast Ranged spells without disadvantage, plus opportunistically blasting the target in the same turn with Scorching Ray or the like... yeah, that could be LOTS of fun, depending on what spell slots you're interested in expending.

What happens if, as they turn to run, you opportunistically cast Shocking Grasp, and hit, which then prevents them from taking reactions? Do they turn and start to run, get shocked, and then not go any further?

 

[Blue]

They still need to trigger the OA, which merely attacking won't do.

And, since you've used your reaction to do this, you don't have another reaction to attack, though others might. Sounds like you are using your OA for the chance to give others OA if they are positioned right. Not a bad trade when you can set it up.

 

[Sezarious]

To answer what you have asked I think we need to ask another question first. Is the movement an enemy makes from failing a save against dissonant whispers TRIGGERED by the reaction OR is the movement the reaction itself.

This was the thought that entered my mind before looking at the PHB and I was actually not confident I would find the answer, but sure enough, the exact wording I could have hoped for was there. Page 190 PHB under reactions "-A reaction is an instant response to a trigger"

This indicates to me that the movement in the above scenario is a type of reaction, therefore if the enemy was then hit with shocking grasp, it WOULD stop him from moving any further.

 

[Riley37]

Variant: the warcaster uses their Action to cast Fear, and an opponent flees, on its action, triggering OA.
My point is that one can use spellcasting to cause an opponent to flee, and that synergizes with Warcaster.

Dissonant Whisper is a super weird rules anomaly, and has been discussed in other threads, because it causes the target to use Reaction and move; being hit with DW is the only way, anywhere ever in 5E, that one can move as a Reaction.

 

[CapnZapp]

Sidetrack: what's so weird about moving on your reaction?