D&D 5E Minor Illusion question

[Lyxen]

I do like how 3e had various subtypes of illusion, such as figments, glamours, phantasms, and shadows that all worked differently ways.

It's still the case, it's exactly the same spells without the tags from 3e, the only thing that they have kept is the school. In most cases, yu can still use the 3e explanation straight out of the box, if you want to go into that level of detail. While it's one area of the game where I still wish that they'd kept some of the 3e tags (I like the kind of intrigue and investigation about types of magic, etc.), overall I agree with the design choice of 5e, because it makes for a more open game and again, after 7+ years of 2-3 campaigns in parallel at all levels, the number of cases where we did have to adjudicate is really low, it was not worth making a more complex game and introducing quite a bit of technical jargon for that.

 

[DEFCON 1]

Since the cantrip specifically says that it can't create light, I'd most likely rule that the cantrip couldn't also block light, but a higher-level illusion probably could. Minor Illusion is such a basic little cantrip spell that I wouldn't give it the ability to something that grand, like snuffing the light from light sources. But if the caster wanted to actually spend a resource to do it-- Silent Image for example-- then I'd go along with it.

 

[Sword of Spirit]

Since the cantrip specifically says that it can't create light, I'd most likely rule that the cantrip couldn't also block light, but a higher-level illusion probably could. Minor Illusion is such a basic little cantrip spell that I wouldn't give it the ability to something that grand, like snuffing the light from light sources. But if the caster wanted to actually spend a resource to do it-- Silent Image for example-- then I'd go along with it.

That’s a good point. As a cantrip it might be better to say that it doesn’t block light or create shadows, and therefore if you aren't careful how you use it others would be able to easily see something isn’t right.

 

[Lyxen]

That’s a good point. As a cantrip it might be better to say that it doesn’t block light or create shadows, and therefore if you aren't careful how you use it others would be able to easily see something isn’t right.

No-one would believe an illusion that lets light through and does not cast a proper shadow, the spell is not that basic.

Moreover, I don't want to go back to the physics debate, but in the real world "seeing through" and "letting light through" is exactly the same thing. An object cannot be both opaque to light reflected from other objects (which is what you can see) and light emitted by other objects, both are light.

 

[DEFCON 1]

No-one would believe an illusion that lets light through and does not cast a proper shadow, the spell is not that basic.

Moreover, I don't want to go back to the physics debate, but in the real world "seeing through" and "letting light through" is exactly the same thing. An object cannot be both opaque to light reflected from other objects (which is what you can see) and light emitted by other objects, both are light.

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.

 

[Lyxen]

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?

No, nothing changes externally, it still blocks the light (it HAS to block the light otherwise it would not block light reflected from other objets anyway and you would see through it) and casts shadows, but YOU can see through it as it looks faint to you. For me, that is the only explanation that makes global sense.

 

[DEFCON 1]

No, nothing changes externally, it still blocks the light (it HAS to block the light otherwise it would not block light reflected from other objets anyway and you would see through it) and casts shadows, but YOU can see through it as it looks faint to you. For me, that is the only explanation that makes global sense.

Different strokes and all that.

 

[J.Quondam]

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.
That's the whole point of the saving throw, imo: Does the viewer spot the discrepancies in and/or because of the illusion, or not?

 

[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.

It's not what the spell says, when someone passes the investigation check, it does not invalidate the illusion, it just becomes faint to that creature. It actually does not even say that the creature can see through it.

 

[J.Quondam]

It's not what the spell says, when someone passes the investigation check, it does not invalidate the illusion, it just becomes faint to that creature. It actually does not even say that the creature can see through it.

True. And my answer in no way invalidates that; I phrased it very carefully for a reason.
Read it again.

* late edit for spelling!