D&D 5E Magic Missile vs. Mirror Image

[Arial Black]

If the caster couldn't figure out which target was me then I don't think they could cast it on me effectively.
To be honest In my games when this Hold Person situation happens I house rule that having multiple images gives a Bonus to the saving throw of the Target. +2 for each active extra image.
My players and I discussed and that is what we came up with.

One of the problems with house ruling one thing is the tendency to then need to make even more house rules to take account of those changes; it's like dominos falling.

In this case, you've house ruled MI to work differently than it says it works (you house rule it to work on stuff that doesn't require attack rolls), now you have to make up more stuff to cope with the consequences of that ruling (MI now protects against all spells that require a target, but have to decide exactly how it protects because that isn't part of the spell description).

Sometimes it better just to go with the RAW. In this case, MI does not affect nor can it be affected by anything that doesn't use an attack roll.

 

[guachi]

Mirror Image is good enough as it is considering it doesn't require concentration. I don't need to be adding more benefits to it like protecting against hold person or magic missile.

I'm with Arial Black on this - KISS. No attack roll? Not affected by Mirror Image.

 

[Arial Black]

My personal ruling is this:

Magic Missile cannot miss something it has targeted.
The caster chooses the target.
Mirror Image creates targets (illusory targets, but still targets).
As such, while the spell cannot miss, the caster can possibly choose the wrong target.

So, what does this mean to me? It means that both spells do what they say they do. Mirror Image creates extra targets. Magic Missile hits the targets at which it is aimed. My ruling would be that the duplicate images could be hit by missiles.

You're correct when you say that "spells do what they say they do".

What magic missile says is:-

Each dart hits a creature of your choice that you can see within range

Therefore, images are not viable targets because images are not creatures.

An attack with a weapon can be aimed at anything: creatures, images, objects, the air, because weapons do not have to obey any spell description because they are not spells.

When seeing a target protected by mirror image it's obviously a single creature with illusions of itself swimming in and out of each other. You don't know which image is real, but you do know that it is one creature. Any spell that lets you target a creature works just fine and mirror image simply doesn't come into it, unless that spell requires an attack roll in which case mirror image kicks in.

 

[robus]

When seeing a target protected by mirror image it's obviously a single creature with illusions of itself swimming in and out of each other. You don't know which image is real, but you do know that it is one creature. Any spell that lets you target a creature works just fine and mirror image simply doesn't come into it, unless that spell requires an attack roll in which case mirror image kicks in.

I suppose it does act more like a homing missile than a javelin. Thanks for the clarification.

 

[Brandegoris]

Mirror Image is good enough as it is considering it doesn't require concentration. I don't need to be adding more benefits to it like protecting against hold person or magic missile.

I'm with Arial Black on this - KISS. No attack roll? Not affected by Mirror Image.

Awww.. You Hatez your playerz

 

[Bacon Bits]

Think of magic missile as an area of effect spell (a strange one, because it can affect some targets more than once).

Mirror image doesn't protect you from fireball or cone of cold or thunderwave. It similarly doesn't protect you from magic missile.

I'd rather think of magic missile as saying you need to make 3(+) ranged spell attacks. Except those ranged spell attacks always hit and never crit, so don't bother rolling.

 

[discosoc]

I'd rather think of magic missile as saying you need to make 3(+) ranged spell attacks. Except those ranged spell attacks always hit and never crit, so don't bother rolling.

Greenstone is correct, though. Mearls (I think it was him) actually used it as an example in a podcast talking about spell targeting.

http://media.wizards.com/2017/podcasts/dnd/DnDPodcast_01_19_2017.mp3

I want to say the conversation starts around the 6 minute mark, but can't remember for sure. your interpretation would actually mess with metamagic feats quite a bit.

 

[Bacon Bits]

Greenstone is correct, though. Mearls (I think it was him) actually used it as an example in a podcast talking about spell targeting.

No, that's how Mearls ruled it. That makes it official, not correct. That's a consequence of "Rulings, not rules."

Personally, I recommend avoiding Mearls & Crawford's responses if at all possible. Seriously. Read through the Sage Advice columns and tweets. You'll find an alarming number of responses that make you say, "Wow, that's exactly the opposite of way I would rule," and more than a few that will make you say, "No, that's completely stupid. I have no interest in playing the game like that." Eventually you'll realize that it's not worth bothering with.

 

[Argyle King]

You're correct when you say that "spells do what they say they do".

What magic missile says is:-



Therefore, images are not viable targets because images are not creatures.

An attack with a weapon can be aimed at anything: creatures, images, objects, the air, because weapons do not have to obey any spell description because they are not spells.

When seeing a target protected by mirror image it's obviously a single creature with illusions of itself swimming in and out of each other. You don't know which image is real, but you do know that it is one creature. Any spell that lets you target a creature works just fine and mirror image simply doesn't come into it, unless that spell requires an attack roll in which case mirror image kicks in.

So, does that mean I would not be allowed to target a harmful illusion with Magic Missile?

If I attempt to use Magic Missile against an illusory foe, does the spell fail?

 

[Arial Black]

So, does that mean I would not be allowed to target a harmful illusion with Magic Missile?

If I attempt to use Magic Missile against an illusory foe, does the spell fail?

Strange as it may seem, an illusion is not a valid target for magic missile. But it's not too strange, bearing in mind that a door, wooden chest, specific body part, fog, none of these are valid targets for MM either.

That doesn't mean that you cannot cast the spell at the illusion/door/chest/eye! What happens if you cast the spell at a non-valid target?

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

Each dart 'hits a creature'. Since spells do exactly what they say they do, then if you cast MM and target an invalid target, the spell does this:- "You create three glowing darts of magical force. Each dart fails to hit what you aimed at, because what you aimed at was not a valid target".

Against an invalid target the spell will still create three glowing darts, they will still streak towards your target, but will have no effect whatsoever.