D&D 5E Minor Illusion question

[KarinsDad]

Regarding the light, I can totally buy that the light still shines through, and the effect of the light source (lighted objects in the room) is readily visible to all.

However minor illusionstill seems like it needs to be mind affecting to some degree because two different creatures can investigate it, one makes the Intelligence (Investigation) check and sees through it (literally), while the other fails the check and sees a solid object. The creature who passes the check realizes that it is an illusion and can see through it, but that does not change the nature of the illusion for everyone else. The other creature keeps on staring at a solid box until they interact with it or pass a check. Even when viewed from a far distance, there is something about viewing an illusion that causes the brain to throw an exception, at least temporarily.

If you view it as "this is the actual image seen" (i.e. the actual light reflected off of the magical image) instead of the brain being misled, then there is no mind affecting involved.

So how does this sound: The illusion is there, but it blocks no light. The illusion tricks the viewer's mind into thinking there is something there.

I still do not think of it as tricking the mind. I think of it as this is the image you see and an intelligent creature can spot the minor discrepancies or errors.

The hard part of this to wrap one's head around is the ability to see past it once it is discovered if it were merely a reflection of normal light off the illusory image (this does not happen with visual illusions in the real world). Figuring it out would not change the light (at least in the real world). So I view it more as "if I shift my head to this angle and tilt it slightly, I can see through the holes and see what is really behind it".

I almost view it as polarized light. When squinting with the eyes just right, one can see past the extra light reflected by the image to the original light reflected (or generated) behind it.

 

[steeldragons]

I would submit it functions just as @jodyjohnson proposes. The room is still "lit" you just can't really see/tell how/from where. Investigation of the room, maybe, (direction of shadows, etc...) determines the light seems to emanate from this iron box bolted to the wall. How strange! Must be magic somehow.

To offer the alternative/contrast, Darkness cast on the torch (or anywhere near it), would block the light being shed...thus plunging the room into darkness (assuming that particular torch was the only light source in the room).

I know 5e doesn't do "reversible" spells, but I use them and would houserule them in when I get around to getting in a 5e game. So a "reversed Light" could produce a small globe of darkness that could be put on/around the torch to snuff out the light in the room...as opposed to "by the book" where the only way to do this is to Darkness [Sphere] an entire 15' rad. sphere area...and a 2nd level spell slot.

The other alternative, any caster with Prestidigitation, Druidcraft (or Thaumaturgy, for that matter, though it's not RAW), should be easily able to snuff out the torch without needing tor resort to illusions. Problem then, of course, is when you want the light again, you need to relight it (which again any of those cantrips will/should be able to do).

 

[Warmaster Horus]

I like that last explanation. The box remains but the source of the light is mysterious, apparently emanating from the box somehow.

 

[Chocolategravy]

The only thing you see is light, it doesn't matter if it comes directly from a torch or if it bounces off a wall first.

If light passes through illusions then the illusion is transparent. It also won't cast or block shadows like an opaque object would. Anything of any significant size would look very strange and be immediately detected as an illusion.

 

[steeldragons]

The only thing you see is light, it doesn't matter if it comes directly from a torch or if it bounces off a wall first.

If light passes through illusions then the illusion is transparent. It also won't cast or block shadows like an opaque object would. Anything of any significant size would look very strange and be immediately detected as an illusion.

We're not talking about, though, "light pass[ing] through [all] illusions". The OP is asking about "Minor Illusion." A simple cantrip. Will the light make the illusion easily detectable? Yes, probably. It's only a cantrip...and a lit room with no visible light source should [hopefully] raise some eyebrows that there is something weird going on.

Also, having just reviewed the Minor Illusion description, the spell stipulates it can not "create sound, light, smell or any other sensory input." So, arguably, it can not "create darkness"/block/change the existing light.

The two -light shed by the torch and the illusion of the iron box- occur simultaneously. Welcome to magic!

And yes, you are correct, the iron box will not cast a shadow and other shadows will not appear on it, seemingly stopping/ending at the box's edge.

If this were "Major Image", a 3rd level spell, which stipulates it "seems completely real" with the potential for multiple sensory inputs/alterations (sight, sound, smell, temperature, etc...)...then yes, I would definitely rule that illusory iron box covering a torch would block the light.

 

[Chocolategravy]

We're not talking about, though, "light pass[ing] through [all] illusions". The OP is asking about "Minor Illusion." A simple cantrip. Will the light make the illusion easily detectable? Yes, probably. It's only a cantrip...and a lit room with no visible light source should [hopefully] raise some eyebrows that there is something weird going on.

Nothing about it being a cantrip means light passes through it.

If light passed through it, then you couldn't see it. It is the light reflecting off it that you see.

The spell creates an image, it explicitly does not create light. In much the same way you couldn't see the image in a dark room, you can't see through the image in a lit one unless the image is of something translucent, like a gem.

 

[KarinsDad]

Nothing about it being a cantrip means light passes through it.

If light passed through it, then you couldn't see it. It is the light reflecting off it that you see.

The spell creates an image, it explicitly does not create light. In much the same way you couldn't see the image in a dark room, you can't see through the image in a lit one unless the image is of something translucent, like a gem.

This is a fine explanation until one considers that once a creature sees it as an illusion, then weird stuff happens.

For example, illusion of a box on top of a lit torch. Nobody sees the torch because of the illusionary box. The room is pitch dark because the illusion blocks the light. Then one PC interacts with the box and he sees a totally lit room whereas the other PCs still see a pitch dark room. Or even alternatively, he sees the lit torch, but the room is still pitch dark.

However one cuts it, it's wonky.

 

[SkidAce]

This is a fine explanation until one considers that once a creature sees it as an illusion, then weird stuff happens.

For example, illusion of a box on top of a lit torch. Nobody sees the torch because of the illusionary box. The room is pitch dark because the illusion blocks the light. Then one PC interacts with the box and he sees a totally lit room whereas the other PCs still see a pitch dark room. Or even alternatively, he sees the lit torch, but the room is still pitch dark.

However one cuts it, it's wonky.

I like the wonky..its all illusions and madness I tell you. Pretty soon the players don't trust anything they see.

P.S. I really like illusory floors over pits. Or illusory pits to make them go a different way...

 

[steeldragons]

Nothing about it being a cantrip means light passes through it.

If light passed through it, then you couldn't see it. It is the light reflecting off it that you see.

The spell creates an image, it explicitly does not create light. In much the same way you couldn't see the image in a dark room, you can't see through the image in a lit one unless the image is of something translucent, like a gem.

You are trying to apply real world physics to magic. Magic, by definition, takes real world physics and ties them into little tangled knots of mess [or this case iron box].

Our games don't have to be the same, obviously. How you choose to define things in your game is...well, fine for you.

In mine, both are possible and occur...cuz aahwooOOooah <jazz hands> mmMagic.

I would also add that it being a cantrip, absolutely, has [or should have] something to do with a given spell's interpretation. Given, also, that the description states it can not "create light" and, so, by extension, can not elicit a change in existing light. So, yes, it being a cantrip does mean light can pass through it...that does not demand you can see inside of or through it...just that this weird ambient light that's in the room seems to "begin" at the edges of the box.

D&D spells are, explicitly, tiered into levels of varying power. 3rd level spells are more powerful/reality bending than cantrips. 5th level spells are more powerful/reality bending than 3rd. It is, and has always been, built into the system that a cantrip would/should be less powerful/reality bending than a more powerful/higher "tiered" spell. All Magic, in D&D, is not created equal. [and specifically, in D&D, illusion magic has always been wonky/required some case-by-case adjudication].

It might be interesting to note, that an image created by Minor Illusion also does not/can not create or effect sound. So that low "rippling" sound of flames burning or occasional flickering "crackling" sound that a torch might produce will still be heard in the room. The odor of smoke/something burning. All of that is still happening.

Again, determining there is an illusion here should not be particularly difficult. But it will/should cause a moment or two to be spent questioning/confused/investigating...by the characters/NPCs, mind. What the players know/can deduce is happening is not [always] what the PCs know/can deduce.

Think of it, maybe, like a one way mirror...kind of...reversed...light gets out but doesn't pierce in. You see the outside of the box because of the light in the room/that is being shed from within it...but you do not actually see the source/light inside the box.

Yes. It's wonky. It's supposed to be. It doesn't make sense when applied to real world physics/how light operates. It's not supposed to. It's magic.

 

[jodyjohnson]

If artists can paint what looks like a 3d image on a sidewalk, I'm confident a magical illusion specialist with a high int can make 'realistic' illusions including shadows (fake shadows).

I don't buy getting a Darkness/Devil's Sight combo on the cheap. But I think that would also be a contrived corner case (rooms aren't usually lit by a single torch).

Most of my rulings would abide by "narrative physics" and not scientific physics. Illusion to hide behind is fine, image as a distraction or action waster would be fine. Minor illusion as 'allies can see, enemy can't' seems out of character since those effects already have spells specifically.