D&D 5E Minor Illusion question

[Chocolategravy]

So what does this mean for the torch in the illusionary box in the dark room?

Is the room pitch dark, or does light come through? I suspect that light comes through with this interpretation since the illusion is transparent (or is it translucent, you used both terms).

Then the box couldn't be seen from the inside as it wouldn't be reflecting light. If it was reflecting light at the proper intensity then none would be going through. The only way to have it both reflect the proper amount of light and transmit the light through would be if the image was making light, and it can't.

If the illusion is an opaque object, it will deal with light like an opaque object would, otherwise it would appear so strange in any room that has light in it, that it would be obvious and useless as an illusion. If the illusion is of a translucent object, it will deal with light like a translucent object would, as again, there is nothing in the spell saying something like a gem or glass is impossible to make, so it would have to deal with light in the same way.

 

[Thyrwyn]

TV screens a create images that do not reflect light. Holograms do not reflect light. Nothing about the laws of physics say that an image must reflect light.

 

[Tormyr]

So what does this mean for the torch in the illusionary box in the dark room?

Is the room pitch dark, or does light come through? I suspect that light comes through with this interpretation since the illusion is transparent (or is it translucent, you used both terms).


This, btw, is similar to my earlier explanation. I was viewing it more as errors in the image that allow someone to squint past it. Yours is a real world illusion where a person perceives something in a default way.

One issue with both interpretations is that people auto-fail. In the real world, some people see past some illusions immediately.

So in this explanation:

What is really going on:
The room is lit by a single torch. The torch has an illusion of a box around it. The "true" state of the illusion is fairly translucent and is the state of the illusion after a successful investigation check. (Sorry for using both "transparent" and "translucent". I caught that for most of them and meant "translucent.")

What the viewer sees from outside the room looking in but not in line of sight to the torch or the box illusion surrounding it:
A lit room with some decent shadows in it. (because the light comes from the single torch)

What the viewer sees on entering the room:
No light source and a box on the wall.

What clues the viewer might pick up that something weird is going on:
All the shadows in the room point to the box being the light source. Looking at the box causes the pupils to constrict a bit. Looking away from the box, the room seems darker for a bit until the pupils dilate back to "normal."

After the successful Intelligence (Investigation) check the box becomes translucent, and the viewer can see the torch and figure out what is going on. It is much like someone who has seen a particular optical illusion before knowing how to switch from seeing the bent lines to knowing how to focus on a portion to validate the lines are straight. Even if the person knows they are looking at an optical illusion and how to beat it, the first instant they see it usually results in the illusion taking effect before they focus on it the right way.

And, hey, auto fail because: magic. But even in D&D we have those who are not instantly fooled. Those with blindsight, truesight, and tremorsense look through it like it is not even there and might not even be able to perceive the illusion.

 

[KarinsDad]

TV screens a create images that do not reflect light. Holograms do not reflect light. Nothing about the laws of physics say that an image must reflect light.

No, but Minor Illusion states that it cannot generate light. TV screens generate light.

 

[KarinsDad]

So in this explanation:

What is really going on:
The room is lit by a single torch. The torch has an illusion of a box around it. The "true" state of the illusion is fairly translucent and is the state of the illusion after a successful investigation check. (Sorry for using both "transparent" and "translucent". I caught that for most of them and meant "translucent.")

What the viewer sees from outside the room looking in but not in line of sight to the torch or the box illusion surrounding it:
A lit room with some decent shadows in it. (because the light comes from the single torch)

What the viewer sees on entering the room:
No light source and a box on the wall.

What clues the viewer might pick up that something weird is going on:
All the shadows in the room point to the box being the light source. Looking at the box causes the pupils to constrict a bit. Looking away from the box, the room seems darker for a bit until the pupils dilate back to "normal."

After the successful Intelligence (Investigation) check the box becomes translucent, and the viewer can see the torch and figure out what is going on. It is much like someone who has seen a particular optical illusion before knowing how to switch from seeing the bent lines to knowing how to focus on a portion to validate the lines are straight. Even if the person knows they are looking at an optical illusion and how to beat it, the first instant they see it usually results in the illusion taking effect before they focus on it the right way.

And, hey, auto fail because: magic. But even in D&D we have those who are not instantly fooled. Those with blindsight, truesight, and tremorsense look through it like it is not even there and might not even be able to perceive the illusion.

This seems reasonable and goes back to Jody's explanation.

CG's explanation that the image blocks light and the room is dark and suddenly, one person can now see the light and see the lit room (because it is magic) is all kinds of wonky (plus it gives a cantrip nearly the power of a darkness spell).

 

[Tormyr]

TV screens a create images that do not reflect light. Holograms do not reflect light. Nothing about the laws of physics say that an image must reflect light.

At least in the TV's case the TV's image creates a decent amount of light that illuminates something, which we are trying to avoid based on the wording of the spell. The hologram is possibly a closer analogy. I am not aware of how much illumination is generated by a hologram (outside of whatever is generating the hologram). In our case, magic would be generating the hologram, so it might not be as much of an issue.

 

[Tormyr]

Then the box couldn't be seen from the inside as it wouldn't be reflecting light. If it was reflecting light at the proper intensity then none would be going through. The only way to have it both reflect the proper amount of light and transmit the light through would be if the image was making light, and it can't.

If the illusion is an opaque object, it will deal with light like an opaque object would, otherwise it would appear so strange in any room that has light in it, that it would be obvious and useless as an illusion. If the illusion is of a translucent object, it will deal with light like a translucent object would, as again, there is nothing in the spell saying something like a gem or glass is impossible to make, so it would have to deal with light in the same way.

If the illusion is very translucent, then it may be blocking back and reflecting only a tiny bit of light that would be fairly imperceptible when looking at the room in general. The creature that sticks their head into the box before realizing that is an illusion would see the threads of magic which compose the illusion, and their mind would fill it in solid. Realizing that it is an illusion allows the faint image to be seen from the inside or the outside.

 

[Tormyr]

This seems reasonable and goes back to Jody's explanation.

CG's explanation that the image blocks light and the room is dark and suddenly, one person can now see the light and see the lit room (because it is magic) is all kinds of wonky (plus it gives a cantrip nearly the power of a darkness spell).

Unfortunately I missed Jody's explanation because I checked out of the thread for a page or two.

CG's explanation was mine initially as well (dark room and all that). Thanks everyone for the discussion. I think I now have an interpretation that fits much better and allows for better play at the table.

 

[bganon]

Enh, if minor illusion affects light as a real object would, then you can make a five-foot wide solar collector and fry your opponents. Even a torch with a five-foot focuser on it would blind anything with eyes. And what part of the spell limits it to visible light? By all accounts it should be able to create a 5-foot cube greenhouse around that torch, blocking escaping IR and heating the interior to hundreds of degrees. Except you can't create "other sensory effects". But light itself can cause other sensory effects. The spell description is inherently contradictory; something somewhere has to give.

Attempts to parse spells as if real-world physics applies almost inevitably lead to contradictory results. That's the "magic" part. If spells followed the rules of nature, they'd just be "science".

 

[Chocolategravy]

This seems reasonable and goes back to Jody's explanation.

CG's explanation that the image blocks light and the room is dark and suddenly, one person can now see the light and see the lit room (because it is magic) is all kinds of wonky (plus it gives a cantrip nearly the power of a darkness spell).

I'm not sure why you're insisting on comparing this to darkness, it is nothing like it. The 5x5x5 cube being one. Moving is another. Yes, you can block a torch that happens to be in a 5x5x5 cube, but ray of frost can just as easily put that torch out, does that make ray of frost more powerful than Darkness?

Put simply, if you use the spell to make an image of an opaque object, like a box, then the image will appear to be an opaque object, like a box, which means you won't see light through it. If you did see light through it, then it would look nothing like an opaque box.

The spell clearly is intended and worded to allow you to make opaque objects of a quality that is not trivial to determine isn't real. This means that it has to be opaque to light or it will be trivial to determine that your weirdly lit shadowless or colored shadow projecting object is not at all the object it is attempted to simulate.

It is irrelevant if the torch is outside the box, inside the box or if the light is meeting the box directly from the light source or bouncing off another object before meeting the box. To appear as if it is an opaque object, IT HAS TO BLOCK LIGHT. If it isn't blocking light, it will not appear to be an opaque object.

Yes, the object blocking light for some people and not blocking it for others seems weird, but if you think about it, it is exactly as weird as any other spell effect that only works on some people in an area and not others. There are many many spells that have exactly the same type of weirdness going on. That is magic for ya.