D&D 5E Magic Missile vs. Mirror Image

[Yunru]

You didn't read the tweets:





Now, follow this logic. The first question is broad enough to cover scrolls, wands, staves, weapons, and even potions and wonderous items, etc. Nowhere do any of the magic item rules state what action using a given item is, just that you can spend an action to use them. So it must be in the item description, right? Yet all the magic items say is, "You can use this to cast a ~spellname~ spell." But given the context of this question, Crowford just said that a magic item has to say, "You can use this object to cast a spell by taking the Cast A Spell action." But nothing does that. Therefore, casting a spell from a magic item is never the Cast a Spell action.

Crawford's gotten sloppy. He answers from memory rather than checking relevant sections, and it shows.

 

[Sorcerers Apprentice]

Crawford's gotten sloppy. He answers from memory rather than checking relevant sections, and it shows.

Maybe so, but the tweets referenced in this thread seem to be 100% in line with the rules.

 

[ThePolarBear]

Therefore, casting a spell from a magic item is never the Cast a Spell action.

Exactly. But as you wrote, you are casting a spell. That's all it takes for invisibility to wear off. And if you still think that it requires an action, would an invisible sorcerer that is subtle casting a counterspell become visible? Yeah, he is still casting a spell, even while not using an Action, in particular a Cast a Spell action, and not making any sort of movement or sound. Still becomes visible, since a spell was cast. And by the way, potions are explicitly exempt from this, as them (and other items) directly apply the spell effect bypassing the cast (all in DMG, page 141, section "Activating an Item", enfasis on the "Spells" subsection)

Just an example: Not all the effects from a Wand of Wonders would break invisibility, as not all effects are "cast". Still a Wand....

By the way, even if the discussion about invisible Dragons (or pretty much every other monster with a special action that's not explicitly an attack or a spell, and there are many) is very interesting... i'll go with <it's not 'makes an attack' but 'attacks', so anything harmful is enough> Yeah, not really a reason, i know, but it's simple and works...

Now, interpreting the remaining elements is difficult, but its difficult primarily because of certain effects only being able to target creatures.

Since "it's impossible to track which image is real" (which by itself is a strange concept, but yeah), the only thing you can do is target "the caster", as those are all "the caster". You can't even track which is "the caster" one, two, three or four. You see 4, but all are "the caster". You attack "the caster" (most likely all of them at once) with your big Axy thing and either 1) You suck so much that you manage to miss an illusion 2) you hit something, and that something might have substance or be completely fake. And then lose track of what you actually hit, because of the movements of the images created by an illusion spell made to mess with your perception are actually messing with your perception.

For Magic Missile it's simple. It can't destroy the images since it's a spell that does not require an attack, like Fireball. It does NOT matter if a single Missile passes through all the images, dancing back and forth... it will land on the caster, and deal damage. All images would then mimic the caster taking damage and all still be up.

Shall we take it up a notch? Let's have a level 20 Warlock have fun and roll an Eldritch Blast at the poor Mirror Image caster. 4 rolls, 4 attacks, 4 images... One each, right? Nope, you can't distinguish which one is which, so you just shoot at 4 targets. That happen to be always "the caster". For you, in your mind.

 

[Arial Black]

I didn't read this whole thread, but I have read quite a few similar threads. Personally I gave up on RAW in 5th edition quite a while ago. Which I think is actually the RAI.

By a strict reading Magic Missile can only target creatures. So you can't hit a door with it, for example. (And I swear this is going somewhere relevant to MM vs. MI. )

So, lets say you see a creature ahead of you in the darkness that is lying on the ground. Now he might be trying to hide, or he could just be dead and lying on the ground. So you cast Magic Missile at him. If he's alive the Magic Missile automatically hits, if he's dead he isn't a valid target for your spell and it fizzles.

Likewise if you target something you think is a creature, but turns out to be a scarecrow, or a dummy, you cast the spell, but it fizzles as the target is invalid.

Personally I rule that no matter what, when you cast Magic Missile, the magical bolts appear and fly at the target you have chosen. If the target is a living creature the magical energy tears into it and does damage. If it is not a living creature then the instant the missile touches the target it bursts into a harmless flash of light and the target is completely unharmed.

If you want to cast Magic Missile at a door? Go for it. It will hit the door and do absolutely nothing. However, if the door turns out to be a Mimic it will rip into it and do some damage.

So for Magic Missile vs. Mirror Image I rule that you choose all of the targets you want to hit. If you want to pick just one for all the missiles, roll to see if you got the right one. If you have 3 missiles and the target has 2 images, plus himself, it is easy. Both images and the target are each hit once. When a Magic Missile hits an image it fizzles as soon as it touches the image, but it also disrupts the image as it is now obvious that it is just an illusion.

If the number of missiles don't match the number of images then I have to reason out how to determine whether the actual target is hit or not, but this is pretty easy. For example, if you have 3 missiles and the target only has 1 image, then just roll like normal to see if the extra missile hits the target or the image. If you have 3 missiles and the target has 3 images then you have to roll a d20 for each missile. On a 6 or higher you hit an image. On a 5 or less you hit the target. Once you hit the target once he can't be hit again, so all other missiles hit, and destroy, an image.

So this is the ruling I have come up with based on the RAW. Some of it is obviously extrapolation, but I don't think any of it directly contradicts the RAW and it makes sense to me from an in-game perspective.

It can be a perfectly internally consistent ruling, but it cannot be based on the RAW while RAW says that it can only target a creature and your rule allows it to target things that are not creatures.

 

[Sebastrd]

It's an action, which makes you make several attacks yes. And among those attacks are actions without attack rolls.

That's untrue. A dragon's multiattack allows it to use Frightful Presence then make several attacks, all of which are attacks. Breath weapons never enter the equation.

 

[Plaguescarred]

That's untrue. A dragon's multiattack allows it to use Frightful Presence then make several attacks, all of which are attacks. Breath weapons never enter the equation.

While a dragon's Multiattack action lets it use Frightful Presence in addition to attacks, it's not an attack in itself it has no attack roll nor does it say its even one so therefore it doesn't fit this category.

 

[Cognomen's Cassowary]

Now I remember why I stopped getting involved in rules discussions. Magic missile fails the basic test for being attack, and somehow the conversation about whether it is one goes on for eleven pages.

 

[Sebastrd]

While a dragon's Multiattack action lets it use Frightful Presence in addition to attacks, it's not an attack in itself it has no attack roll nor does it say its even one so therefore it doesn't fit this category.

My apologies for being unclear; that's exactly what I meant to imply. You and I are in agreement.

 

[Sebastrd]

Crawford's gotten sloppy. He answers from memory rather than checking relevant sections, and it shows.

It's rather comical that you accuse him of making the same mistake you are guilty of in this very thread. See above.

 

[Ovinomancer]

Now I remember why I stopped getting involved in rules discussions. Magic missile fails the basic test for being attack, and somehow the conversation about whether it is one goes on for eleven pages.

So does a dragon's breath, which says to me that such a narrow reading of the definition of attack isn't very useful. Reading it as something as an attack if and only if it uses an attack roll or says explicitly it's an attack leads to the odd situations where something that would normally be considered an attack isn't one. Especially since the wording can easily be read without the "and only if" and it still makes sense. This latter method doesn't have odd corner case issues and works better with the design goal of natural language instead of terms of art.