D&D 5E War Caster and spells that allow saves at end of target’s turn

[Pickaxe]

War Caster and spells that allow saves at end of target’s turn

The War Caster feat allows you to cast a spell targeting one creature on a target that provokes an opportunity attack. A spell like Hold Person allows the target to repeat a save at the end of its turn. Since reactions like OAs interrupt turns, if a target fails the initial save, would it essentially get an immediate second save, representing the end of its turn? Or would the spell last until the end of the target’s next turn?

 

[Hjorimir]

Interesting question. I think we're looking at 2 saving throws (assuming the first one fails).

 

[Satyrn]

I'd definitely go with them getting that essentially immediate second save.

If the opportunity attack hold person winds up having no effect, the wizard should learn not to use it next time.

 

[Pauper]

By the text of the spell, the target would get to make a Wisdom save at the end of its turn -- "At the end of each of its turns, the target can make another Wisdom saving throw. On a success, the spell ends on the target."

I'd argue that the spell is still useful even if the target makes the save at the end of its turn; the effect of the spell essentially ends the target's turn, so it it didn't attack before moving away and provoking the Opportunity Attack, it didn't get to attack. Likewise, its movement stops immediately due to the effect of the failed save on the Hold Person spell.

A more interesting wrinkle is that War Caster prevents you from targeting more than one humanoid when casting Hold Person with a spell slot higher than 2nd level -- and, based on your DM's interpretation of the War Caster spell selection restriction, may prevent you from using Hold Person with a higher-than-2nd-level slot at all, since casting Hold Person with a higher level spell slot allows the caster to target additional humanoids even if she doesn't actually do so or have other humanoids within the appropriate area of effect to target more than one opponent.

--
Pauper

 

[Volund]

What happens if there is an ally next to the War Caster who also gets an opportunity attack? There is no turn order for opportunity attacks, but someone has to go first.

War Caster gets an opportunity attack and casts Hold Person. Target fails save. At this point the target is paralyzed and can't do anything further on its turn.
What happens next?
A) The ally gets its opportunity attack against the paralyzed target. Then the target's turn ends and it gets its second saving throw.
B) The target is paralyzed, effectively ending its turn, so it immediately gets another saving throw. The ally would have had an opportunity attack but now the target has not in fact left the ally's reach, so there is no opportunity attack anymore.
C) The target is paralyzed, effectively ending its turn, so it immediately gets another saving throw. The ally still gets an opportunity attack, but not until after the target's second saving throw, so this attack might be against a paralyzed target depending on the result of the second saving throw.

Related question:
What happens if the War Caster lands Booming Blade and the target chooses to stay in place instead of continuing its movement out of the reach of both the War Caster and their ally?