How does Ring of X-Ray Vision interact with Illusion spells and similar effects?

Question

Specifically, the ring states that "solid Objects within that radius appear transparent and don't prevent light from passing through them". Does it apply to solid objects created through illusion?

It seems unlikely that the ring works selectively, and illusions can't plausibly "know" they are being viewed in that way.

By extension, the Ring of X-Ray Vision seems to allow its wearer to inspect the internal organs of a person (be it through selective sight if we consider it to work like Superman's X-Ray Vision, or by standing 30 ft from the intended target so that the target's body is only partially within the ring's radius (RAW explanation). If that's the case, do spells like Disguise Self also disguise the internal organs of an affected character in such a way as to fool a person with a Ring of X-Ray Vision?

For example, would the user of Ring of X-Ray Vision be able to tell if a target has a second heart, or has only one lung, or is undead (dead organs) if that target is affected by spells like Disguise Self?

Moreover, would a Ring of X-Ray Vision allow its user to see selectively through clothes? If so, what about illusory clothes and other illusory objects? I am thinking that it should, otherwise its wearer could use it to automatically detect any illusion, which is not what it says in the description (no truesight, just see through solid objects).

Answer 1

Yes, you can see through illusions of objects. No, you can't see if a creature is missing a lung.

The ring of X-ray vision doesn't allow you to see through creatures, only objects, so if someone makes an illusion of a wolf, you can't see through it (even partially). If someone makes an illusion of a wall, then you can see through it, because until you save vs the illusion, you treat it as if it were real, which means that with your ring of x-ray vision, it is considered an object that you can look through.

Also consider the alternative: that you can't see through the illusion. That means that you would automatically detect any illusory objects withing 30', because, suddenly, there's a wall, or large rock, barrel, crate, or whatever that you can't see through, making it incredibly obvious.

Answer 2

It doesn't do what you think it does

While wearing this ring, you can use an action to speak its Command Word. When you do so, you can see into and through solid matter for 1 minute. This vision has a radius of 30 feet. To you, solid objects within that radius appear transparent and don't prevent light from passing through them. The vision can penetrate 1 foot of stone, 1 inch of common metal, or up to 3 feet of wood or dirt. Thicker substances block the vision, as does a thin sheet of lead.

You can see through objects; you can't see through creatures. Further, you can no longer see the objects you can see through until you reach the distance at which your x-ray vision can't penetrate. So, you can't look inside a living creature and you can only see inside a dead body if it is more than 3-foot thick (assuming it's made of flesh).

You should picture yourself standing in a 30-foot "bubble" where all objects disappear unless they are thicker than the specified dimension. Assuming you are standing on the earth, looking down, you see nothing for 3-feet.

Interaction with illusions

An illusionary object/creature behaves as an object/creature; each illusionary effect has its own rules for what it can and can't do and for when it is revealed to be an illusion (and what happens then as well) so it's impossible to generalize.

X-ray vision is not Truesight so unless the specific illusion has something to say about it (AFAIK, none do), being able to (or not able to) see through it makes no difference.

Answer 3

A creature is not an object

Basically everything physical in the D&D multiverse is either a creature or an object, and virtually never both. A creature upon death becomes an object, namely a corpse. That corpse can become a creature through necromancy! Perhaps the best way to consider the difference is to look at the spell true polymorph.

A creature typically falls into one (or more) of the following categories:

• Aberration
• Beast
• Celestial
• Construct
• Dragon
• Elemental
• Fey
• Fiend
• Giant
• Humanoid
• Monstrosity
• Ooze
• Plant
• Undead

If it's not one of those, it's probably an object.

Does it make sense that a magic ring can see through objects but not creatures? No, but it's magic so sense need not apply. The Ring of X-Ray Vision allows you to treat objects as if they were transparent (clear like a window) to see what's on their other side (up to the limitations of 1 ft. of stone, 1 in. of common metal, 3 ft. of wood or dirt, or any thin layer of lead.)

Is an illusion an object? Typically No

Illusions are not real. If you disprove them, they often turn faint and transparent. They are tricks of the eye, or the mind. If illusions were real, the Wizard School of Illusion level 14 feature Illusory Reality would be a real dud. And furthermore, the description specifies a solid object. Unless an illusion says that it creates an object, it does not.

Conclusion

With the Ring of X-ray Vision, Yes, you can detect most illusions because they will not be affected by the magic of the ring. Perhaps you'll get an Intelligence check (Investigation) at that point, because you will have a reason to doubt its authenticity. What a phantasm does to make you justify its true threat might be up to your DM to decide.

Answer 4

No, you can't see through Illusions that aren't solid matter.

I agree with the answers that state that you wouldn't be able to see through illusions, so long as you can actually interact with them. (You wouldn't be able to see through Silent Image for example, since it's not solid matter).

The main reason I'm submitting a separate answer is because I disagree with the other answers on this point:

Yes, it could be used to see into or through a Creature.

The answers here are all referring to the one bit of text that you quoted from the ring's description. looking at the full text of the ring, it states:

While wearing this ring, you can use an action to speak its command word. When you do so, you can see into and through solid matter for 1 minute. This vision has a radius of 30 feet. To you, solid objects within that radius appear transparent and don't prevent light from passing through them.

So it seems as if it contradicts itself. In one line it says 'solid matter', and in another 'solid objects'. I'd say because objects are made of matter, the more general case would be applicable here. On another note, it seems unlikely to me that the intention was to exclude Creatures from the effect.

Now it does also seem to suggest that the object as a whole must be in the radius for this to take effect, so unless the creature is more than 3ft thick, I don't think you'd be able to see into it.

With all that in mind

Let's circle back to the original question and look at Disguise Self spell as an example. The spell states:

The changes wrought by this spell fail to hold up to physical inspection. For example, if you use this spell to add a hat to your outfit, objects pass through the hat, and anyone who touches it would feel nothing or would feel your head and hair.

Because the illusion is not solid matter, the Ring of X-Ray Vision wouldn't be able to see through it. This would immediately tip anyone off using X-Ray vision, because they wouldn't be able to look into or through the disguised individual as they would normally; the illusion would hold up.