6

Does a reaction that causes me to move out of range after the spell is cast but before the spell hits cause it to miss?

A couple ways this can be done are

  • Readied action to move with a trigger: target casts the spell
  • Mage Slayer feat with a melee weapon attack that moves the caster
David Coffron
  • 74,667
  • 14
  • 306
  • 503

3 Answers3

14

The spell would hit (pending a successful roll)

There is no time differential between spellcasting and 'hit' when dealing with Instantaneous casting times.

If a spellcasting has been completed, we look at the duration to understand how long the effect lasts/takes. If the spell is Instantaneous, then

The spell harms, heals, creates, or alters a creature or an object in a way that can't be dispelled, because its magic exists only for an instant.

In addition, Range is no longer a factor once cast:

Once a spell is cast, its effects aren't limited by its range, unless the spell's description says otherwise.

Therefore, a spell that has completed it's casting with an instantaneous effect would deliver that effect before the target had an opportunity to move.

The only way to move out of range would have been to do so before the casting was completed

NotArch
  • 125,044
  • 39
  • 506
  • 804
11

The spell still hits

In any reaction that occurs when the spell is cast, "when the trigger occurs, you can either take your reaction right after the trigger finishes or ignore the trigger. (PHB 193). As such, the spell will still be cast and is governed by this rule from the Range section of Spellcasting:

Once a spell is cast, its effects aren’t limited by its range, unless the spell’s description says otherwise.

So, no matter how far away you move from the reaction, the spell attack will follow you.

David Coffron
  • 74,667
  • 14
  • 306
  • 503
  • 1
    @NautArch The question does say after the spell is cast. – David Coffron Mar 05 '18 at 16:55
  • @NautArch You could have just done it on your own turn, then. – Please stop being evil Mar 05 '18 at 17:02
  • The "reflex saving throw for half damage" for cases like a fireball also seem to be a proof for this. It actually simulates the effect the OP was looking for: it can be interpreted as jumping/rolling away from the spell, but still being scorched by it passing next to you. So there is no need for a separate handling of a "jumping away" action. – vsz Mar 06 '18 at 07:10
  • @vsz We are talking about spells with attack rolls; It is Dexterity saving throw; and you dont move when you make a save like this – David Coffron Mar 06 '18 at 07:26
3

The spell would hit you

According to the rules for readying actions:

...decide what perceivable circumstance will trigger your reaction...

When the trigger occurs, you can either take your reaction right after the trigger finishes or ignore the trigger.

The trigger of "being targeted" with a spell is tricky, as I don't believe it is "perceivable" as is required by the Ready action until the spell is actually cast. Identifying who a spell is going to target before cast could be house ruled but RAW there is nothing to indicate that the actions required to cast a spell indicate the target until the spell occurs.

Since the trigger completes, the spell is cast, at which point you're already targeted, and the spell goes off before you are able to move. In the case of firebolt, the projectile simply moves too fast.

Sir Cinnamon
  • 6,466
  • 1
  • 27
  • 54
  • 3
    There is considerable disagreement on this point; the wording of the trigger is important. https://rpg.stackexchange.com/questions/92023/can-you-use-a-readied-action-to-avoid-an-attack/92024#92024 – keithcurtis Mar 05 '18 at 14:55
  • I see, I was taking for granted that "targeted" is only perceivable on a spell being cast and not before - I'll add that in. – Sir Cinnamon Mar 05 '18 at 14:58