D&D General Seeming, Non-Detection & True Sight

[TaranTheWanderer]

Seeming is a suped up Disguise Self using an illusion to make you look like someone else.
True seeing Is a divination that lets you see everything for what it really is.
Non-detection makes you immune to being targeted by divination magic and perceived through scrying sensors.

I've always ruled that 'see invisibility' and 'truesight' turn the target's eyes into the magical sensors - for the purposes of spells like Mind Blank and Non-Detection. So an invisible person with Non-detection or Mind Blank could not be seen with a 'See Invisible Spell'.

The question is this: What happens to the Seeming when someone has True Sight? Is the Seeming immune to being perceived by magic in that way? Does the Seeming melt away but the person underneath remains 'disguised'?

I'm just curious how one might adjudicate it.

 

[Dragongrief]

As written, Truesight allows you to auto-detect visual illusions and succeed in the check/save against them.

For Seeming, a successful check means that you know the creature is disguised - no more or less.

So if a creature with Truesight saw something under the effects of a Seeming, they would know it was disguised, but not see its actual appearance.

 

[Iry]

Depends on the DM. I count most illusion spells as being transformed by magic, while others might rule it requires literal transformation.

In the former, the truesighter sees both the illusion and the original. In the latter, the truesighter knows she is looking at an illusion, but cannot see through it.

But that's specific to Seeming. Many illusion spells have a clause about becoming translucent on a successful perception/save.

 

[prabe]

Huh. If it were a creature with inherent truesight (some fiends have it, for instance) I'd presume it'd see through the illusion; I'd figure the true seeing spell to work similarly. I think my thinking is that it's targeting the illusion, not the person, so neither nondetection nor mind blank would prevent that. Which is weird, because I'm generally a pretty pro-illusion DM. Same with the see inisibility spell: I don't think the invisible creature is the target.

I don't think that's how I would have guessed my thinking would go.

 

[TaranTheWanderer]

Huh. If it were a creature with inherent truesight (some fiends have it, for instance) I'd presume it'd see through the illusion; I'd figure the true seeing spell to work similarly. I think my thinking is that it's targeting the illusion, not the person, so neither nondetection nor mind blank would prevent that. Which is weird, because I'm generally a pretty pro-illusion DM. Same with the see inisibility spell: I don't think the invisible creature is the target.

I don't think that's how I would have guessed my thinking would go.

I’m assuming the spell true-seeing and not an ability from a creature. Non detection protects from divination spells so I assume it wouldn’t work against a creature’s natural ability.
These spells are target self or touch. But non detection protects from sensors. I’ve always interpreted these divination spells as giving you the sensory capability to detect things (like invisible creatures) and I’ve always considered that new magical perception a type of sensor that non-detection would protect you from.

 

[Bacon Bits]

Seeming doesn't have any special resistance to True Seeing.

I might allow True Seeing to pierce Nondetection, but I would never allow it to pierce a Mind Blank. However, the three spells are written in an "immovable object vs irresistible force" manner. It's entirely up to the DM.

 

[J.Quondam]

However, the three spells are written in an "immovable object vs irresistible force" manner. It's entirely up to the DM.

Ooh... Sounds like a great opportunity to whip out the old "when they come into contact, it rips a hole in space-time, dealing 10d6 damage to everyone in a 100 ft radius and sucking them to a random plane of existence" trope.
That'll teach those prying truesighted eyeballs!

 

[Aelryinth]

As written, Mind Blank and Non-Detection protect you against divination effects. They don't protect the spells upon you from being noted by Divination effects.
Thus, you can see the invisible. Them being Mind Blanked/Non-detected does not change the fact you can see the invisible now (they aren't a target of the spell, it's general use) being invisible is not protected.

On the other hand, it will prevent you from having the information that you are 'in disguise' plucked out of anywhere, so Seeming would if you were protected. On its own, True Sight would see right through the illusionary part of the disguise.

If you want to compete, general defensive spells have the advantage, and overcome attacks of their own level and lower. Thus, Non-Detection cast out of a 3rd level Slot should trump any detect spells of level 3 or lower.
True Seeing being higher would then naturally trump Non-Detection, but not Mind Blank.

Just remember that a Divination spell that enhances you and does not require a target is probably not foiled by Mind Blank. Mind Blank doesn't protect that illusion you're under, it protects you.