Does Mirror Image affect spells that have no attack roll?

Question

I have two questions concerning the mirror image spell.

1. If I am under the effect of mirror image and was targeted by a spell like blight, do I roll a 1d20 to determine whether myself or an image was targeted? It doesn't make an actual attack, but common sense suggests that casting a spell still requires a solid target which has to be determined between me and my illusory images.

2. The same question, but about magic missile. I googled it and found nothing but theories. Does Magic Missile hit and destroy all images at once or just one? Rules say that you can choose several targets, but according to the mirror image description you cannot target the image exclusively.

Answer 1

Mirror image only affects attacks, and blight and magic missile aren't attacks.

Mirror Image (PHB p.260):

Three illusory duplicates of yourself appear in your space. Until the spell ends, the duplicates move with you and mimic your actions, shifting position so it’s impossible to track which image is real. You can use your action to dismiss the illusory duplicates.

Each time a creature targets you with an attack during the spell’s duration, roll a d20 to determine whether the attack instead targets one of your duplicates.

If you have three duplicates, you must roll a 6 or higher to change the attack’s target to a duplicate. With two duplicates, you must roll an 8 or higher. With one duplicate, you must roll an 11 or higher.

A duplicate’s AC equals 10 + your Dexterity modifier. If an attack hits a duplicate, the duplicate is destroyed. A duplicate can be destroyed only by an attack that hits it. It ignores all other damage and effects. The spell ends when all three duplicates are destroyed.

A creature is unaffected by this spell if it can’t see, if it relies on senses other than sight, such as blindsight, or if it can perceive illusions as false, as with truesight.

Attacks are only things that require an attack roll (weapon attacks and spell attacks). See P. 194 of the PHB:

If there’s ever any question whether something you’re doing counts as an attack, the rule is simple: if you’re making an attack roll, you’re making an attack.

("Attack" has a specific rules meaning in 5e that isn't the same as its ordinary English meaning; actions and spells that might be described as attacks in ordinary language aren't necessarily attacks as far as the 5e rules are concerned.)

If a spell doesn't say that the caster makes a spell attack, then mirror image doesn't interact with it. This is clear from the complete spell description above: the spell effects only occur if the caster is targeted with an attack, and its effects consist only of changing the target of the attack to one of the duplicates. The only way to determine if a duplicate is hit is by resolving the attack against the duplicate's AC. There is no provision for mirror image interacting with spells that (for example) require the target to make a saving throw.

It might be argued that the first paragraph, particularly the phrase it’s impossible to track which image is real, establishes that mirror image makes reliably targeting the caster with any effect impossible. There are other spells that interfere with the targeting of non-attack spells, and they spell out those effects specifically:

Nondetection (PHB p.263):

The target can’t be targeted by any divination magic ...

Antimagic field (PHB p.213):

Spells and other magical effects, such as magic missile and charm person, that target a creature or an object in the sphere have no effect on that target.

If mirror image affected the targeting of non-attack spells, we would expect there to be a specific clause in the description that spells that interaction out. For example, something beginning with "When a creature targets you with a non-attack spell ... ". But there is no such wording; the effects described apply only to attacks.

It might also be argued that mirror image clearly creates illusions which are valid targets for spells, so a hostile spellcaster might target one of these illusions by accident.

However, mirror image doesn't create illusions; it creates illusory duplicates, and it specifically spells out all of their effects. Spells that create illusions (such as major image or minor illusion) have different effects (and they don't specify what happens if they are targeted by a spell, attack or otherwise).

So, to consider the two spells in the question:

Blight (PHB p.219):

Necromantic energy washes over a creature of your choice that you can see within range, draining moisture and vitality from it. The target must make a Constitution saving throw.

Magic missile (PHB p.257):

You create three glowing darts of magical force. Each dart hits a creature of your choice that you can see within range.

(emphases mine).

Magic missile just hits the actual creature being affected by mirror image, and doesn't affect the images at all. It's not an attack, because no attack roll is made; it just does damage. Blight likewise ignores the images and affects the target, as it also is not an attack.

Answer 2

Those spells are not attacks and therefore bypass mirror image

Mirror image explicitly states (PHB 260):

Each time a creature targets you with an attack during the spell’s duration, roll a d20 to determine whether the attack instead targets one of your duplicates.

Functionally, spells such as magic missile and blight work on sight and the issue is that there are now up to 4 targets in the space occupied by the true target. However, we must now parse the language of the spell as written above. Unfortunately, it does dictate "targets you with an attack".

Now, how does one define attack? @Marq's answer points to a previously answered question: What Counts As An Attack.

Therefore, magic missile and blight are not attacks, and so they bypass mirror image.

This is also supported by an unofficial tweet by rules designer Jeremy Crawford:

The mirror image spell has no effect on magic missile, which doesn't involve an attack.

Answer 3

By the Rules as Written, mirror image creates illusions.

There is additional text that details how mirror image interacts with attacks. Magic missile and blight are clearly not attacks:

If there’s ever any question whether something you’re doing counts as an attack, the rule is simple: if you’re making an attack roll, you’re making an attack.

so the clauses about what happens when you are attacked do not apply.

Here is the mirror image spell description with all of the "when attacked" parts removed:

Three illusory duplicates of yourself appear in your space. Until the spell ends, the duplicates move with you and mimic your actions, shifting position so it’s impossible to track which image is real. You can use your action to dismiss the illusory duplicates.

A duplicate can be destroyed only by an attack that hits it. It ignores all other damage and effects. The spell ends when all three duplicates are destroyed.

A creature is unaffected by this spell if it can’t see, if it relies on senses other than sight, such as blindsight, or if it can perceive illusions as false, as with truesight.

There is no "flavor text" in 5e spell descriptions: everything in the above description still applies to the spell interacting with non-attacks.

So the question becomes, what happens when someone creates an illusion of a creature that is indistinguishable from the creature?

What happens when you cast magic missile on an illusionary dragon? Does the spell fizzle? Is believing the target is a creature enough to make it a legal target to magic missile?

We now look at the rules for targeting a spell:

Targets

A typical spell requires you to pick one or more targets to be affected by the spell’s magic. A spell’s description tells you whether the spell targets creatures, objects, or a point of origin for an area of effect (described below).

Unless a spell has a perceptible effect, a creature might not know it was targeted by a spell at all. An effect like crackling lightning is obvious, but a more subtle effect, such as an attempt to read a creature’s thoughts, typically goes unnoticed, unless a spell says otherwise.

So you have to pick a target.

There are 4 things in a square that look indistinguishable, and are swapping location constantly.

By the rules as written, the character must choose a target. Barring being able to see past the illusion, the character is not able to distinguish valid targets from invalid ones. What happens when a spell that targets creatures targets an illusion is not clear from the rules.

How the chosen target is picked is not dictated by the rules. Doing anything except a random choice is going to be hard to justify, however, as the spell caster can (by the rules) not distinguish between the real target and the illusions.

There is a bunch of rules text on how it works when you make an attack; the fact this isn't an attack doesn't mean that the spell has no effect.

Answer 4

Both blight and magic missile are still attacks, they just simply require no attack roll. In the case of blight you would roll to see if it affects the target or an image, if it affects an image, the image is destroyed. You would do the same for all the missiles of a magic missile spell together (since they all strike simultaneously). Potentially all missiles might strike the target, or they might strike an image and thus destroy it.

Answer 5

Contra the above interpretation, since the attacker is making a choice as to what image to attack in both Blight and Magic Missile, the d20 roll does apply, because both Magic Missile and Blight are both attacks, in that they cause damage to the target. Furthermore they require the attacker to SEE the target which is protected by the Mirror Image in effect - whose very nature is visual.

If the attacker is super-intelligent maybe he can pierce the illusion, but otherwise Mirror Image should apply.

Answer 6

The mirror image spell description says:

A duplicate can be destroyed only by an attack that hits it. It ignores all other damage and effects.

The condition that a duplicate can only be destroyed by an attack that hits it explicitly excludes attacks that do not hit it, like an area spell (fireball) or that have other effects. The key here is that it ignores all other damage and effects. For it to ignore other damage and effects, it means either an area effect or a targeted effect.

The rule on spell targets states:

A typical spell requires you to pick one or more targets to be affected by the spell’s magic.

If a spell requires a target that the spellcaster can see, then he is seeing up to four identical targets, but he can only target one of them. To determine which target the spellcaster selected, we need to use the rule given by the spell to pick targets for an attack as the spellcaster is affected by this spell.

The only exceptions are explicitly stated in the spell description:

A creature is unaffected by this spell if it can’t see, if it relies on senses other than sight, such as blindsight, or if it can perceive illusions as false, as with truesight.

By analyzing only the statement about an attack and its definition, the rest of the spell rules are being ignored, specifically this last part. We have to consider everything.

So, considering everything, all attacks that require an attack roll are subject to the target selection rule of the spell, as well as any spell that requires the selection of a target that the spellcaster can see, provided the spellcaster isn't unaffected by one of the conditions specified. If the spell causes damage only to the target and the selected illusionary target takes damage, it can be destroyed by that spell's damage. Any other effects on the targeted illusionary target are ignored.

To answer the specific questions then:

1. You roll a d20 to select the target for the blight spell. If it targets one of the illusionary duplicates, it has no effect.
2. You roll a d20 to select the target for each magic missile bolt. The selected target takes damage accordingly and can be destroyed or hurt.

Answer 7

Yup, agreed that this was also how one bypassed Mirror Image(MI) in previous editions, not that this has any bearing on 5e where rules seem to contradict others at every turn for ease of use vs crunch.

Where previous editions of Magic Missile(MM) started with a single dart and ramped up every few levels thereafter, MI images would disappear in a flash from a higher level spell caster, saving the protected Spellcaster a few darts of pain, but eventually overwhelming one’s defences.

This is how our table rules it. RAI from a very non-crunchy WoTC GM in Mr. Crawford’s interpretation - respectfully, of course!

As a few others have said, if you only have the capability of targeting someone visually, then the end result of this means, a random image(or self) is hit.

Unfortunately, this is possibly moot since the missiles will technically remove all of the images with a single casting of MM. Then again, they do flex and intermingle with one another so the argument could still be made for rolling a d20 for each dart and having the capability of targeting the same image...they don’t impact, singly, one at a time - they fly and collide with targets simultaneously.

This is where having a historical context of the spell in previous editions is handy for those GMs not accepting of anything less than sneaking in the tiniest bit of crunch back into D&D!

Answer 8

"Both blight and magic missile are still attacks, they just simply require no attack roll." "'If you don't make an attack roll, it is not an attack.'" This is more twisted up than a pretzel.

They are illusiory DUPLICATES and therefore can be targeted by anything. They also have the same saving throws as the character they are duplicates of. "The duplicate's AC is 10 plus the dexterity modifier of the duplicated creature"

"A duplicate can be destroyed only by an attack that hits it. It ignores all other damage and effects."

This states that even if you take the, 'the word attack is vague, spells aren't attacks they're spell attacks' then that means that the duplicates cannot be destroyed by spell attacks period. It would mean that only melee weapons, crossbows, and other ranged weapons can hit them because "they are attacks." Which doesn't sound like a reasonable rule to me so I'm counting that out of the runnining.

This also says that other spells such as, charm person, sleep, and hold person would also have no effect on them but would show the same response as if a regular character just resisted the spell.

Blight would cause a saving throw, on a success the duplicate is as unaffected as a regular character, but on a failure it dissapates as if an arrow had hit it.

If you believe you are looking at an enemy you can throw something at it regardless of whether or not you hit it, this is true to real life as well as D&D. You could cast magic missile and only hit a duplicate, but if you do that it's your own fault because at level one, the spell already creates enough magic missiles to hit each duplicate and the enemy using the spell at once. So if you put all your eggs in one basket that's seriously your own funeral.

I hope that will answer the question.