Illusions and light

[Warlush]

So neither silent image nor major image mention creating bright or dim light. It also doesn't specify how the illusion interacts with existing light.
For example does an illusion of a candle produce a range of bright and dim light the way a real candle does? Does an illusory wall cast a shadow?
I rule yes to both in my games, but how about y'all?

[Tanarii]

It's pretty reasonable to consider that Light is a phenomena. So a follow up question is do these spells limit you to causing an object or a phenomena, or allow an object that usually has an associated phenomena as a single casting? RAW appears to pretty definitively be one or the other, but I can see someone ruling they come together in certain cases like this.

It shouldn't interact with real objects though. D&D uses zone based light rules, so sure allow zones of bright or dim light. But no casting shadows specifically. Static shadows should be easy to replicate though, just don't light those areas up. Moving creatures in the area would give away the game pretty quick, but that's easy enough ... treat those as physical interaction.

In short, you only run into trouble if the candle generates radiating light and you try to figure out the rules of magic based on physics or something. :smallamused:

[Keltest]

My general thought is that it cant create real light that reacts the way light does, but it can create fake light, and its ability to react is based on the flexibility of the spell. So Major Image could be used to create, say, a candle that has light out to 20', and the light generated will adapt to the environment and react realistically as long as you use your action to keep the adaptation going. But if you weren't maintaining that flexibility and somebody, say, walked in range of the candle, they would be a rather odd looking silhouette unless and until you created an appearance for them, and it would likely strain the illusion beyond most peoples' belief, and is also beyond the bounds of Major Image, specifically.

In other words, you can create the illusion of a lit area, but not light, if that makes sense.

[Segev]

If you allow light as a phenomenon, I see no reason said light would not behave like light (barring the illusionist deliberately making it fail to do so). I also am not one to quibble over the specifics of exclusive or inclusive “or” wrt phenomena + object + creature. Consider that “an orc” could come with armor and weapon, which are definitely objects, plural.

The important thing is that silent and major image make only one “thing.” One orc, one couch, one fog bank, one campfire. I think getting hung up over whether that is an object AND a phenomenon is losing sight of the narrative and mythical role the spell is supposed to play: a single illusion.

Now, up until this thread pointed out that silent image and major image did not specify they couldn’t create light, I’d have said they couldn’t do so. So I learned something new today!

The final question, which is important, is whether the light can be real enough to illuminate real things, or can only be illusory and this only illuminate parts of the illusion. Does it only look like light, but fail to make real things in it any brighter?

[Tanarii]

Now, up until this thread pointed out that silent image and major image did not specify they couldn’t create light, I’d have said they couldn’t do so. So I learned something new today!
I did a double take and went and checked too. It's almost certainly because we've both been in many Minor Illusion threads, and it's somewhat fixed in our minds that it can't create light.

What worries me now is I might have made incorrect table rulings in the past based on that :smalleek:

[Derpy]

The image is purely visual; it isn’t accompanied by sound, smell, or other sensory effects.

I'd say light creates an other sensory effect beyond the image; and wouldn't allow it. I'd understand why people would allow it, however; but I personally hate illusion power creep. I'd allow it for major image, but if a creature other then the caster steps inside it, they've physically interacted with the light and know it's an illusion.

[Keltest]

I'd say light creates an other sensory effect beyond the image; and wouldn't allow it. I'd understand why people would allow it, however; but I personally hate illusion power creep. I'd allow it for major image, but if a creature other then the caster steps inside it, they've physically interacted with the light and know it's an illusion.

I think the fact that adding illumination introduces so many extra moving parts is exactly why it isn't power creep. You can get a little more use out of the spell, but in exchange it is much, much harder to pull it off without just automatically tipping your hand.

[Pex]

It can't brighten the area outside the area effect of the spell volume, but the caster can illuminate however he wants within the area. If the area was originally dark or dim it doesn't matter. It's illusionary illumination. If the caster doesn't know what particular objects are in the area they remain the same illumination as always as does everything else. Nothing is really brighter, but everything is covered over by the illusion. If an observer who knows the area well finds it odd a particular object isn't there he knows should be there or even the illumination looks odd, that's what the Investigation check is for. If the observer fails to beat the DC then he fails to see through the illusion.

[Derpy]

It can't brighten the area outside the area effect of the spell volume, but the caster can illuminate however he wants within the area. If the area was originally dark or dim it doesn't matter. It's illusionary illumination. If the caster doesn't know what particular objects are in the area they remain the same illumination as always as does everything else. Nothing is really brighter, but everything is covered over by the illusion. If an observer who knows the area well finds it odd a particular object isn't there he knows should be there or even the illumination looks odd, that's what the Investigation check is for. If the observer fails to beat the DC then he fails to see through the illusion.

Except it cannot create light, it can create an illusion; for silent image (in particular, I'll concede that major image as it specifically gives examples that it can make whatever created extend to the senses above and beyond the object, but silent image specifies it does not.), one that cannot effect the senses beyond the illusion. Shedding light in an area is beyond it's scope. That illusion doesn't fill in the blanks in illumination because it cannot.