Hey folks,

situation:

In a room of total magical darkness (for the sake of argument say lvl 9), the PC wants to create an illusion using Major Image of fireworks. Would you rule that the fireworks light up the room or the room stays dark?

I ruled that because the flashes are figments of the imagination, they would not illuminate the room.

How would you do it?

I would say that the fireworks have the illusion of creating light, but do not actually light anything up. Like, light is being cast, and would show silhouettes theoretically, but they would still be darkened and obscured normally as if in magical darkness.

I'd let it work, I like it.
That's a 3rd level spell slot, the use is creative.... yeah, I like it!

Not to say you were wrong with your ruling. I'm just more lax now that my beard is grey and I have to get up to piss 5 times a night.

Considering that the spell says 'it seems completely real', I'd consider allowing illumination within the 20 foot cube area of effect, but not beyond.

However, as some illusion spells (like blur or mirror image explicitly state that their illusions only affect creatures using sight, ruling that there is no illumination is also not wrong.

My final decision would depend on what effect the outcome would have had. Foiling a 9th level spell cast explicitly to create magical darkness to ward a wizard tower? No way a 3rd level illusion would have a chance...

I'd argue it cannot light the room but within the area of the illusion you can make it appear what you want. So you could make the illusion of an area lit up but it's only showing an illusion not what is actually there so if an enemy moved into the area, the players would still only see the lit up area and not the enemy.

You could also make illusions that can be seen despite the darkness - like a large floating toothy maw or big menacing glowing eyes or sparks and fireworks - they don't illuminate the area but the players still see them against the backdrop of pure darkness.

Technically they couldn’t cast major image as it requires being in a spot that they can see and if we are taking magical darkness to be RAW darkness spell they can’t see. Also I believe it’s stated in basic rules that illusions will look like a light but not emit any. So you would not be able to use it to illuminate magical darkness.

Quote from sardonicmonkey >>

Technically they couldn’t cast major image as it requires being in a spot that they can see and if we are taking magical darkness to be RAW darkness spell they can’t see. Also I believe it’s stated in basic rules that illusions will look like a light but not emit any. So you would not be able to use it to illuminate magical darkness.

 That was my take as well. They targeted an area outside the darkness with the area effect extending into the darkness. That part was fine but RAW darkness doesn't allow any light to pass. I said they could see the flashes but they flashes would be only in their mind, not illuminate the room. But technically, they wouldn't be able to see anything at all.

If they were in magical darkness abd could not see how did they see a spot outside the darkness to cast it in?

Quote from Wysperra >>

Quote from sardonicmonkey >>

Technically they couldn’t cast major image as it requires being in a spot that they can see and if we are taking magical darkness to be RAW darkness spell they can’t see. Also I believe it’s stated in basic rules that illusions will look like a light but not emit any. So you would not be able to use it to illuminate magical darkness.

 That was my take as well. They targeted an area outside the darkness with the area effect extending into the darkness. That part was fine but RAW darkness doesn't allow any light to pass. I said they could see the flashes but they flashes would be only in their mind, not illuminate the room. But technically, they wouldn't be able to see anything at all.

 It's your ruling, stand by it.
Too many people get caught up in RAW RAW RW.... I despise that term, in my 40 years of playing this game I've never seen it used more than the last 5 years.
Spell said they need to see the place to cast the spell, you ruled otherwise in this instance. You allowed their creativity but didn't let them completely step out of bounds. And THAT is what being a DM is about... else it might as well be a computer game.
The DM runs the game - not a book.

My only point is that it isn’t specifically “in their minds” but an actual visible effect created by the spell. If it doesn’t work because the area cannot be seen, or because the magical darkness still overpowers the light from the fireworks then those are perfectly legitimate reasons for the spell to not work, but the spell not creating actual sensory phenomena is a different matter entirely.

Quote from sardonicmonkey >>

If they were in magical darkness abd could not see how did they see a spot outside the darkness to cast it in?

 They are in a lit hallway. The room before them is in magical darkness.

Quote from IamSposta >>

My only point is that it isn’t specifically “in their minds” but an actual visible effect created by the spell. If it doesn’t work because the area cannot be seen, or because the magical darkness still overpowers the light from the fireworks then those are perfectly legitimate reasons for the spell to not work, but the spell not creating actual sensory phenomena is a different matter entirely.

 Similar to phantasmal killer. There isn't anything actually there, it is a figment of the mind. So the target can see it and feel it because they believe it, but there isn't anything there. 

Quote from Wysperra >>

Quote from IamSposta >>

My only point is that it isn’t specifically “in their minds” but an actual visible effect created by the spell. If it doesn’t work because the area cannot be seen, or because the magical darkness still overpowers the light from the fireworks then those are perfectly legitimate reasons for the spell to not work, but the spell not creating actual sensory phenomena is a different matter entirely.

 Similar to phantasmal killer. There isn't anything actually there, it is a figment of the mind. So the target can see it and feel it because they believe it, but there isn't anything there. 

 I disagree with that interpretation. It is not described in any way as a figment of the mind, but instead as actual images in space and time. Phantasm Killer specifies that the image is in the creature’s mind, but Major Image makes actual illusions in space like holodeck images, except not solid.

 Illusions, at least in 5e, are not "imaginary". They're not real, per se, but they are actual magical effects. This means they can affect the environment around them, even if that effect is usually (but not always) limited to sensory deceit. Some are entirely in one creature's mind, others seem to be more like effects that are located in a fixed (or moveable) place. Either way, it's worth remembering that the specific description of a spell is important to determine its effects- more than schools are, generally speaking. In this case, Major Image creates an, well, image of an object, creature, or visible phenomenon.

As to whether that visible phenomena (as fireworks detonating would be) illuminates the room and how that works mechanically, it is up to you as a DM. However, I don't think it's outside of reason for a 3rd level spell to light up a room, even if that's not an explicitly indicated interaction. After all, a lot of visible phenomena emit light, and while the description omits light specifically from the description, it can cause a change in sound, smell, and temperature to reflect the image. I think light is mechanically speaking a part of a visible phenomena, so I would limit the effect of the light (at least the brightest or emitting portion of the light) to that 20 foot cube, but I see no reason why within that space light could not be created by the spell- light itself probably falls into the category of "visible phenomenon". Just remember that any creature that knows that it is an illusion would benefit less from the effect- bright light becomes dim, for example, because the sensory effects of the illusion are reduced (so any creature that makes its save, is within the area of the spell, or who cast the spell itself would not get the full benefit). Since the spell itself is contesting magical darkness, you might rule that it does not benefit the caster or anyone who knows it's an illusion much or at all because of that property, but I wouldn't say that the spell doesn't work because of the darkness, rather that it doesn't work because of that final sentence.

(Also, the level at which magical darkness is cast would not matter- it only impacts 2nd level or lower light emitting spells, and that effect does not change, even when cast at higher levels. If it did so, it would be specified.)

Quote from IamSposta >>

Quote from Wysperra >>

Quote from IamSposta >>

My only point is that it isn’t specifically “in their minds” but an actual visible effect created by the spell. If it doesn’t work because the area cannot be seen, or because the magical darkness still overpowers the light from the fireworks then those are perfectly legitimate reasons for the spell to not work, but the spell not creating actual sensory phenomena is a different matter entirely.

 Similar to phantasmal killer. There isn't anything actually there, it is a figment of the mind. So the target can see it and feel it because they believe it, but there isn't anything there. 

 I disagree with that interpretation. It is not described in any way as a figment of the mind, but instead as actual images in space and time. Phantasm Killer specifies that the image is in the creature’s mind, but Major Image makes actual illusions in space like holodeck images, except not solid.

 If that were the case it would fall under transmutation or conjuration or evocation. School of illusion deals with things that are not real.

Can you use Major Image to start a fire? Create water to put out a fire? Blow a toy boat across a pond? Create a hole int he ground or fill it up? 

edit: HA! I can't believe I made a real/not real reference for D&D.

No, it doesn’t create actual fireworks, but it does create intangible images, sounds, and even smells of those fireworks. So the things are not “real,” but they aren’t only in the mind of the observer unless the spell specifically says so.

DMG Chapter 10: Illusion spells deceive the senses or minds of others. They cause people to see things that are not there, to miss things that are there, to hear phantom noises, or to remember things that never happened. Some illusions create phantom images that any creature can see, but the most insidious illusions plant an image directly in the mind of a creature.

Quote from Wysperra >>

DMG Chapter 10: Illusion spells deceive the senses or minds of others. They cause people to see things that are not there, to miss things that are there, to hear phantom noises, or to remember things that never happened. Some illusions create phantom images that any creature can see, but the most insidious illusions plant an image directly in the mind of a creature.

 Right, and major image and minor illusion are “deceive the senses” and “create phantom images that any creature can see” types of spells.

Quote from Wysperra >>

DMG Chapter 10: Illusion spells deceive the senses or minds of others. They cause people to see things that are not there, to miss things that are there, to hear phantom noises, or to remember things that never happened. Some illusions create phantom images that any creature can see, but the most insidious illusions plant an image directly in the mind of a creature.

 The very thing you quoted states that Illusions come in two varieties, one type that creates actual sensory input and another type that is only mental images. It explicitly states that there are two types of illusions and that they are not all purely in the mind of the observer.

Are you trying to say that phantom images are real images and should affect inanimate objects?