D&D 5E Minor Illusion question

[Crimson Longinus]

Sure... but then you also get the issue though that once the illusion is disbelieved it becomes translucent... which means the darkened room now suddenly lights up because the illusion is now translucent from disbelief and the black box surrounding the campfire lets all its light through? That seems kind of silly as well. "I don't think that box is real!" and then suddenly the dark room lights up. Meh. Not for me.

For me, it just comes down to easiest case scenario-- the room or area is lit up like it normally is with the light given off by the campfire/torch, but the illusory box looks solid wherever it was placed in/over the campfire/torch. Then when the box is disbelieved and becomes translucent, you now can just see the wavy image of the campfire/torch behind it (but the light in the area doesn't change at all.)

As far as the reason why it works like this? It's magic-- it just does.

I don't know. I think a model where your perceptions of illusions and any extended effects they might have is subjective is consistent. If you are affected by illusions it blocks light for you, so to you the room looks dark, if you're not affected by it it doesn't block light for you and the room seems lit to you. Is it weird? Well, yes, but it is magic.

 

[Crimson Longinus]

Also, can illusory torch illuminate things? Perhaps it all is just in your head? You think you see a well lit room, but the contents of the room are illusory too? They have no bearing to actual contents of the room, which you do not in reality see...

My head hurts...

 

[Swarmkeeper]

At our table, the Minor Illusion cantrip cannot be used to imitate a Darkness spell by "covering" the only light source in a 20x20 room.

 

[J.Quondam]

I don't know. I think model where your perceptions of illusions and any extended effects they might have is consistent. If you are affected by illusions it blocks light for you to you room looks dark, if you're not affected by it it doesn't block light for you and the room seems lit to you. Is it weird? Well, yes, but it is magic.

Exactly. Illusions (well, many of them, at least) are funky because they depend upon both an actual effect, and on the perception of that effect. In that way they sort of straddle the line between mind-affecting enchantment and magic (or any other mechanics) with definite effects. Pretty much any non-obvious ruling on the exact behavior of an illusion will necessarily cause collisions between those two things, every time.

And that fine. IMO, illusions (and enchantments), in are okay to behave in weird, occasionally unpredictable ways. Because it's magic!

 

[DEFCON 1]

I don't know. I think a model where your perceptions of illusions and any extended effects they might have is subjective is consistent. If you are affected by illusions it blocks light for you, so to you the room looks dark, if you're not affected by it it doesn't block light for you and the room seems lit to you. Is it weird? Well, yes, but it is magic.

Of course... the loss of light in a room blocked by an illusory box around a light source means that the illusion is no longer a 5' cube then, is it? The Minor Illusion is now out to as far as the light would travel, directly in opposition to the size of the spell description.

If you are outside at night and the entire area is lit up by a campfire-- a 60' radius area at least-- and a "solid box" illusion is cast over said campfire... by the reckoning of people here, those of the characters who believe the box illusion see all the light disappear and the entire 120' diameter area go into darkness, whereas those who are immune to the illusion continue to see the 120' diameter circle still lit up. Which means that the illusion is no longer just a 5' diameter cube, but is now a 120' diameter area where the illusion of darkness now covers everything.

Again... if that's how you choose to run it, more power to you. But for my money that just seems silly for a cantrip.

 

[tommybahama]

Again... if that's how you choose to run it, more power to you. But for my money that just seems silly for a cantrip.

The definition of a cantrip in the PHB is "a spell that can be cast at will, without using a spell slot and without being prepared in advance. Repeated practice has fixed the spell in the caster's mind and infused the caster with the magic needed to produce the effect over and over. A cantrip's spell level is 0."

It is never defined as just a silly spell. Cantrips can be deadly after all. There are leveled spells that are weaker than some cantrips.

​

 

[gatorized]

We're talking about a world where gravity is binary (either 0G or 1G), and magically propelled ships that leave the atmosphere bring along enough air in their gravity envelope to last their crew for months.

We're also talking about a world where you can use permanent magic items to create machines that break the laws of thermodynamics in all kinds of ways.

Discussing what D&D illusions can do by using modern concepts of physics seems to me a losing proposition.

No one is forcing you to be here. If you don't want to participate in the discussion, or contribute anything useful or interesting, you are free to leave.

 

[DEFCON 1]

The definition of a cantrip in the PHB is "a spell that can be cast at will, without using a spell slot and without being prepared in advance. Repeated practice has fixed the spell in the caster's mind and infused the caster with the magic needed to produce the effect over and over. A cantrip's spell level is 0."

It is never defined as just a silly spell. Cantrips can be deadly after all. There are leveled spells that are weaker than some cantrips.

​

Right. Still silly for the ability of a cantrip.

 

[Crimson Longinus]

Of course... the loss of light in a room blocked by an illusory box around a light source means that the illusion is no longer a 5' cube then, is it? The Minor Illusion is now out to as far as the light would travel, directly in opposition to the size of the spell description.

If you are outside at night and the entire area is lit up by a campfire-- a 60' radius area at least-- and a "solid box" illusion is cast over said campfire... by the reckoning of people here, those of the characters who believe the box illusion see all the light disappear and the entire 120' diameter area go into darkness, whereas those who are immune to the illusion continue to see the 120' diameter circle still lit up. Which means that the illusion is no longer just a 5' diameter cube, but is now a 120' diameter area where the illusion of darkness now covers everything.

Again... if that's how you choose to run it, more power to you. But for my money that just seems silly for a cantrip.

I am really not advocating for the approach, but I think it is pretty logical, albeit perhaps produces somewhat unintuitive effects. Besides, the illusion already affects things outside of its area; after all, it can be seen from outside of it! (And in case of higher level illusions heard and smelled from outside of it.

 

[Lyxen]

For those who fail their save, an illusion looks like it blocks light.
For those who make their save, the illusion does not look like it blocks light.

The problem with this is that it extends the influence of the illusion way too much around the landscape for such a simple spell, it's no longer a simple illusion of an object, but it influences everything someone in the same area believes to be lit or not.