Casting an Illusion of light

[Brock Samson]

Inspired by the Spellcraft vs. Illusions thread I was just reading, say you're in a completely dark cave, and you cast a Silent Image of a gigantic Fireball slowly descending on your enemies. Does this actually create light? Can you choose to fail your will save to see the light? If the enemies pass their save will they remain in the dark, while those who fail their save assume they're about to be hit by something awful and start running in fear?

[Starbuck_II]

Inspired by the Spellcraft vs. Illusions thread I was just reading, say you're in a completely dark cave, and you cast a Silent Image of a gigantic Fireball slowly descending on your enemies. Does this actually create light? Can you choose to fail your will save to see the light? If the enemies pass their save will they remain in the dark, while those who fail their save assume they're about to be hit by something awful and start running in fear?
I'm not sure if creates light.

Well it says: these spells are useful for confounding or delaying foes, but useless for attacking them directly.

So while it might make them run from it, as soon as they are hit by it, they will realize, it is an illusion.
It has no temperature or sound which are big clues that something is off.

[Oscredwin]

It would create light. What Silent Image does is create light in a form that people will think that there's a solid object there. One of the reasons I'm not allowed to play illusionists anymore is that I would do things like create mono-directional blinding light, blinding everyone past a certain "wall". There are all sorts of ways to play with sensory experience that dont map to real objects.

[Toliudar]

It would create light. What Silent Image does is create light in a form that people will think that there's a solid object there. One of the reasons I'm not allowed to play illusionists anymore is that I would do things like create mono-directional blinding light, blinding everyone past a certain "wall". There are all sorts of ways to play with sensory experience that dont map to real objects.

...or map to the parameters of the spell. There is no game-specific amount of light that blinds people. Saying that you're creating a wall of light bright enough to blind doesn't mean you can actually have that effect, any more than creating a very bright light shining in one direction creates your very own Death Laser:


Because figments and glamers (see below) are unreal, they cannot produce real effects the way that other types of illusions can.

Personally, I'd allow a silent image to create light (although it's useful to note that, if you don't allow illusions to create light, you have the interesting and possibly abusable situation of a Silent Image spell that only affects creatures with Darkvision.

[Curmudgeon]

say you're in a completely dark cave, and you cast a Silent Image of a gigantic Fireball slowly descending on your enemies. Does this actually create light? Yes, it creates light.

Figment

A figment spell creates a false sensation. Those who perceive the figment perceive the same thing, not their own slightly different versions of the figment. (It is not a personalized mental impression.)

Can you choose to fail your will save to see the light?
A character faced with proof that an illusion isn’t real needs no saving throw. If you're casting, you've got proof that it's not real and therefore the rules say you don't need a saving throw.

If the enemies pass their save will they remain in the dark, while those who fail their save assume they're about to be hit by something awful and start running in fear?
Saving Throws and Illusions (Disbelief)

Creatures encountering an illusion usually do not receive saving throws to recognize it as illusory until they study it carefully or interact with it in some fashion. A successful saving throw against an illusion reveals it to be false, but a figment or phantasm remains as a translucent outline. Your Silent Image can only move within the cubes allowed by that spell, and only on your turn when you make it move. So to simulate a giant ball of fire (not a Fireball spell) slowly descending with time for enemies to scatter, you'd need to have enough cubes to move it partway down on the casting round, with more cubes left for the following round. So it might be possible to get enemies to move out of the way. But they wouldn't get any saving throws until they interacted with the spell, which means contact. So pretty much everybody else will be able to see the bright illusion, whereas you'll just see a dim outline.

As for whether the light of the illusion is enough to illuminate the surroundings, that's going to be up to your DM.

[Brock Samson]

And so if you cast an illusion of utter darkness/opaque fog, you'd automatically recognize it as illusion, but provided no enemies are encompassed by the illusion they would probably assume it were more liek Obscuring Mist/Darkness and not get a save unless interacted with?

I have a new trick!

[Cespenar]

I believe that illusion of a fireball would seem like it's bright and shedding light, but it actually wouldn't illuminate the surroundings.

[hushblade]

If the enemies pass their save will they remain in the dark,
I'd say no. The save is to believe the illusion, not to be aware of it or not.

while those who fail their save assume they're about to be hit by something awful and start running in fear?
That would be accurate.

[nedz]

Yes, you can use an illusion to create light, but bear in mind that light works differently in D&D: it has a finite, and quite short, range.

A more interesting question is :

Can you cast an illusion to create darkness ?

I'm pretty sure that this would also work, but there are three things to bear in mind about darkness in D&D: it has a finite, and quite short, range; it spreads just like light; its only actually shadowy.

[Menteith]

Yes, you can use an illusion to create light, but bear in mind that light works differently in D&D: it has a finite, and quite short, range.

A more interesting question is :

Can you cast an illusion to create darkness ?

I'm pretty sure that this would also work, but there are three things to bear in mind about darkness in D&D: it has a finite, and quite short, range; it spreads just like light; its only actually shadowy.

Sure. Wall of Gloom is a spell - it seems reasonable that Silent Image could create an effect that looks identical to WoG. It would also be reasonably strong, since arguably there's no way to "interact" with the illusion.

[moritheil]

...or map to the parameters of the spell. There is no game-specific amount of light that blinds people. Saying that you're creating a wall of light bright enough to blind doesn't mean you can actually have that effect, any more than creating a very bright light shining in one direction creates your very own Death Laser:

Yeah, at best your DM might allow a -1 dazzling penalty if your opponents were vulnerable to light. But he's not obligated to give you anything - unless you're a Gnome Shadowcaster or something, and your low-level illusions gain the power to actually do nasty things.



Personally, I'd allow a silent image to create light (although it's useful to note that, if you don't allow illusions to create light, you have the interesting and possibly abusable situation of a Silent Image spell that only affects creatures with Darkvision.

There exists some precedent in the Ring of the Darkhidden. (You become invisible - only to darkvision.)