Can Gem of Seeing be used from Ethereal Plane to pierce illusion on Material Plane?

[arkieNork]

came up in Slumbering Tsar campaign.
There is a lich in town that is always under effect of Seeming to appear as a human man

Party has found a Gem of Seeing. They know the man is powerful in some way and everyone is scared of him, but they don't know in what specific way he is powerful. They don't want to provoke him in any way and there are no safe opportunities for anyone to hold up a magic gem to their eye and look at the lich normally.

They want to use Ethereal Jaunt to have a party member try to observe the suspect from the Ethereal Plane. I am not sure if the True Seeing effect on the Gem of Seeing would work in that scenario to see through the lich's illusion.

on the one hand in True Seeing spell's description there is mention about being able to specifically see Ethereal creatures from Material plane but not the other way around. There is also this part

>In addition, the spell effects cannot be further enhanced with known magic

One could argue that using Ethereal Jaunt to try and see from Etheral to Material is an attempt to further enhance the spell.

On the other hand Ethereal Jaunt says

> An ethereal creature can see and hear on the Material Plane, but everything looks gray and ephemeral. Sight and hearing onto the Material Plane are limited to 60 feet.

there is no restriction here that illusions should somehow be treated differently when seeing the Material Plane.

So right now I am leaning towards 'their plan should work, let them see the lich's true form'

Before making that ruling, want to know if I am missing or misinterpreting some rule?

[Inevitability]

A creature under true seeing can 'see through illusions'. The relevant factor here is whether you can see the illusion, and in this situation, you clearly can.

True Seeing doesn't generate an area of illusion-detection, it grants its subject the ability to distinguish reality from illusion. How the photons arrive at your eyes doesn't really matter, what matters is that once they do, you know whether their source is illusionary or not. It's a very simple mechanism and carving out exceptions for photons that went material -> ethereal -> eye doesn't make a ton of sense.

(then again, the whole concept of the ethereal plane results in some headscratchers if you think about it for too long, but if we take it at face value for now then the spell clearly works through the ethereal)

[arkieNork]

(then again, the whole concept of the ethereal plane results in some headscratchers if you think about it for too long, but if we take it at face value for now then the spell clearly works through the ethereal)

Thank you for clarifying. Can you expand a bit more on about the headscratchers on this?

[Inevitability]

Thank you for clarifying. Can you expand a bit more on about the headscratchers on this?

Light flows from the material to the ethereal (material objects are visible there). Light does not flow from the ethereal to the material (without magic, there's no seeing the ethereal).

Is every source of light just randomly less powerful in D&D because it's lighting the transitive planes as well? Do torches randomly flare up when you walk into the Beastlands, as there's no longer any plane overlapping? If I bounce a ray of light between perfectly reflective mirrors, will it slowly disappear into another plane?

Wait... is this why D&D spot checks scale so poorly with distance? Maybe seeing things 200 feet away really is impossible because the ethereal plane eats most light at that range!

[Chronos]

Lots of optics-related questions just don't work right in D&D, if you try to actually make sense of them.