Blindness and Illusions

[Etrivar]

Do Illusions actually create patterns of light at the specified location, or do they simply tell the minds of the people subject to them that they see what isn't there?

I'm wondering because I was just struck by an odd thought:

If a character were blinded by a problem with their eyes (destruction, removal, et cetera), their brain would still be capable of processing visual input, it would simply have nothing to give it input. Therefore, if Illusions put the image directly into the mind, a blind person would 'see' it.

This would be rather useful to a party as an easy Illusion-Detector: "It's ok everyone, Thorald can see the dragon, it's not real"

[Cog]

...or do they simply tell the minds of the people subject to them that they see what isn't there?
The lack of the (mind-affecting) tag strongly suggests that this isn't the case; the inability of most illusions to create negative/concave spaces (you can make an illusion of a door, but not an open hall) seems to agree as well.

[Shade Kerrin]

Figments, Glamers and Patterns quite strongly imply the creation of their light/sound patterns in the air itself.
Phantasms(was that the right word?) generate their effects purely in the mind of the affected. However, Phantasms also have a tendency to be single-target only
Shadows tend to be conjurations with glamers painted over the top.

[Kantolin]

Illusions don't target people, they more or less create something. The something they create isn't real, but it's still created over there.

Relatedly, as a note, images that aren't silent image also provides other senses beyond just visual, such as Major Image:


This spell functions like silent image, except that sound, smell, and thermal illusions are included in the spell effect.


So it wouldn't then work on someone who was blind, deaf, and unable to smell or feel but could still sense the world around them (Mindsense?)

This, in and of itself, is actually a detection method though if you do have that (Wait, that dragon doesn't show up on mindsense or sommat), but that's a lot harder than blindfolding yourself and seeing if it still registers. ^_^

[Etrivar]

Ok, most of what I've heard so far makes sense, but I have two questions:

1. If a Phantasm did generate an image in the mind of a blind person, would they be able to automatically succeed on their Will save?

2. The amount of effect that a shadow spell has on the target is determined by whether or not the person believes it is real. What this suggests to me is that even being imbued with shadow-stuff to make it real, it is at least a little bit mind-effecting. Does that sound right? If yes, how would that interact with the idea listed in the original post?

[HalfDragonCube]

That gives me an idea for a wizard spell to research!

Some kind of phantasm that shows exactly what is around you.

Useful for blind people and those already affected by phantasms.

[cfalcon]

Figment say!

"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.)"

So, while not strictly a mental impression, it's something that works on the level of impressions. It doesn't create light, or anything physical, but yet in creates false sensations in those who perceive it.

I would interpret this to mean that someone who has their eyes closed or is otherwise blind, is not visually perceiving it, and therefore can't see anything visual. Someone who is deaf or has their ears plugged isn't perceiving it audially and the sound parts won't be helpful, etc.

[Gnaeus]

That gives me an idea for a wizard spell to research!

Some kind of phantasm that shows exactly what is around you.

Useful for blind people and those already affected by phantasms.

Sounds a lot like blindsight.

[HalfDragonCube]

Sounds a lot like blindsight.

Yep! Except this is a reasonable excuse for it not to go under divination.

Edit: Or transmutation

[Shade Kerrin]

Ok, most of what I've heard so far makes sense, but I have two questions:

1. If a Phantasm did generate an image in the mind of a blind person, would they be able to automatically succeed on their Will save?

Not really. The 'appearance' of a Phantasm is typically not determined by the caster, but by the mind of the victim. Therefore, to one who cannot even imagine sight, it will not take a visual form. Further, they tend to work by provoking fear on a primal level. Finally, the fact that they automatically provoke a Will save, rather than awaiting some sort of interaction, implies that they are already invoking something that the mind should realize is not actually real.

[Qwertystop]

Not really. The 'appearance' of a Phantasm is typically not determined by the caster, but by the mind of the victim. Therefore, to one who cannot even imagine sight, it will not take a visual form. Further, they tend to work by provoking fear on a primal level. Finally, the fact that they automatically provoke a Will save, rather than awaiting some sort of interaction, implies that they are already invoking something that the mind should realize is not actually real.

1) It could still work on someone who's just had their eyes put out
2) No need for fear, that's just the typical use
3) The mind should realize that if the person's eyes were removed last year, they cannot see anything.

[erikun]

Note that illusions are typically more than just sight - sound, touch, temperature, and so on are transmitted in all but the most basic ones. A blind character facing a Silent Image would not be able to tell it apart from the scenery, because they couldn't see either one. Anyone who interacts with a Silent Image will automatically tell that it isn't real, and anyone with extrasenory abilities (i.e. Blindsight) would also be able to automatically detect the illusion.

A blind person attacked by a Shadow Conjuration or something similar wouldn't have any bonuses. They wouldn't be tricked by the visual component, but they wouldn't be able to see it either. The other components would still register as the working illusion though, and the character would still get a save to realize it as a shadow illusion. I suppose you could rule that a blind, deaf, leperosic, etc. character would automatically save from the illusion part and only be affected by the shadow part of the spell, but a character with basically no sensory input probably won't be important enough to have a large enough HP pool to matter.

[Shade Kerrin]

1) It could still work on someone who's just had their eyes put out
2) No need for fear, that's just the typical use
3) The mind should realize that if the person's eyes were removed last year, they cannot see anything.

The point of Phantasms is that they twist your mind to change your perceptions. In essense they bridge the gap between Illusion and Enchantment. Ultimately whether you should get a will save based on conditions is up to the GM, but looking at a list of phantasmal spells:

Phantasmal Killer/Assailants etc: Instantaneous effect. It doesn't matter if you can logically realize that they are fake, all that matters is the instant.
Dream/Nightmare etc: You are dreaming anyway, illogicity is the name of the game.
Delusions of Granduer/Sollipsm: These lean quite heavily on the side of Enchantment, and do not specify the use of any sense
Cone of Dimness/Sensory Deprivation: These are sense robbers, having one less to start with doesn't change the fact that you lost the others. Incidentally, Cone of Dimness is redundant in the case of blindness
Pantasmal Decoy: This one is less sturdy ground, I'd essentially leave it to the GM