D&D | 5E | RAW | regarding natural Truesight with Detect Magic

[smp4life]

There is a box in a room. It is magical but has Nystul's Magic Aura on it to make it appear mundane.

A creature with natural true sight comes into the room & casts Detect Magic.

Does the box appear magical or mundane to this creature.

I would argue no but my player says yes.

[Man_Over_Game]

There is a box in a room. It is magical but has Nystul's Magic Aura on it to make it appear mundane.

A creature with natural true sight comes into the room & casts Detect Magic.

Does the box appear magical or mundane to this creature.

I would argue no but my player says yes.

I'd say both. Blindsight and normal vision aren't mutually exclusive. The entire point of Truesight is having the power to see through illusions, but I'd assume that means you can still recognize illusions, which means you'd see them as both.

[Rentirith]

With the wording of truesight as a type of sense used in the Monster Manual:


A monster with truesight can, out to a specific range, see in normal and magical darkness, see invisible creatures and objects, automatically detect visual illusions and succeed on saving throws against them, and perceive the original form of a shapechanger or a creature that is transformed by magic. Furthermore, the monster can see into the Ethereal Plane within the same range.

Magic aura uses the following wording for an object to create a false aura:

You change the way the target appears to spells and magical effects, such as detect magic, that detect magical auras. You can make a nonmagical object appear magical, a magical object appear nonmagical, or change the object’s magical aura so that it appears to belong to a specific school of magic that you choose.

Thus, because truesight only reveals the presence of visual illusions, and Nystul's magic aura makes a magic items' aura disappear, the two do not interfere and truesight wouldn't reveal the spell or the aura. I am not sure about the interaction between detect magic and magic aura however; Magic aura seems designed specifically to counter detect magic, but it only affects the object it is attached to. So would detect magic fail against the object, but then reveal the aura, rendering the latter spell completely moot?

[firelistener]

I'd probably rule that the aura confounds truesight. The spell description specifically states that Divination spells give false information, so the Detect Magic won't work normally no matter what. Truesight is intended to be super useful, but Nystal's Magic Aura seems to be one of the very few things it can't work against.

That said, I might allow a difficult skill check for someone to realize it's obviously been tampered with in some way.

[Ninja_Prawn]

I agree with Rentirith's logic. Nystul's magic aura is designed specifically to counter detect magic, so you have to rule that detect magic does not give away the presence of the Nystul's magic aura spell. Any yeah, strictly speaking, changing an object's aura isn't a visual illusion. Truesight lets a creature see the object as it is, but Nystul's magic aura doesn't change what the object is, only how it appears to divination magic.