Is there a solid ruling as far as true seeing a person attuned to the amulet?

The innate sense of some high cr creatures would work, the spell True seeing should not.

That would fall under "specific beats general rules." In this case, the amulet trumps the spell. The amulet does one thing, and one thing only, and that is to screw up divination spells like true seeing.

True Seeing gives you Truesight, rather than actually doing any detecting of its own. You also don't count as a magical scrying sensor.

So, by the written rules, I think you could still be detected by someone using that spell.

However, I think the intention is that it wouldn't work.

A creature that \natively\ has Truesight I think could still detect you though, even if you're invisible or in darkness.

Amulet of Proof against Detection and Location:- "While wearing this amulet, you can’t be targeted by Divination spells or perceived through magical scrying sensors unless you allow it."

Truesight:
- If you have Truesight, your vision is enhanced within a specified range. Within that range, your vision pierces through the following:

- Darkness. You can see in normal and magical Darkness.
- Invisibility. You see creatures and objects that have the Invisible condition.
- Visual Illusions. Visual illusions appear transparent to you, and you automatically succeed on saving throws against them.
- Transformations. You discern the true form of any creature or object you see that has been transformed by magic.
- Ethereal Plane. You see into the Ethereal Plane. See also appendix A (“Transitive Planes”).

Truesight is neither a Divination Spell nor a Magical Scrying Sensor, so the Amulet does nothing to protect you from it, as it falls outside of its parameters of protection.

>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.

True sight\^

>Amulet of Proof against Detection and Location
Wondrous item, uncommon (requires attunement)

While wearing this amulet, you are hidden from divination magic. You can't be targeted by such magic or perceived through magical scrying sensors.

Amulet\^

They don't actually have any direct interaction OP unless the person wearing the amulet is shapeshifed but even then the amulet doesnt stop truesight seeing their true form. So I think we need a bit more context here to answer your question properly.

If its the spell true seeing your asking about then it still circumvents the spell as it grants the target truesight not a truesight like effect or a scrying sensor. But thats a bit more up to DM interpretation.

Also, even if truesiggt is a divination, it doesnt target anyone except the person(s) gaining truesight

>True Seeing gives you Truesight, rather than actually doing any detecting of its own.

Tautological reasoning is tautological.

Believe it or not it's our groups changeling that has the amulet. And the question would be if said changeling was under the affects of invisibililty

God damn changlings of course.

Yeah true sight will not only see them through invisibility but also see their true form.

The spell true seeing RAW also but it feels like the RAI is for the amulet to trump that so its DMs FIAT

They don’t seem to interact with each other. Truesight innate from a creature is not a spell, even if it is a magical effect. It also isn’t a scrying sensor or a Divination spell.

Truesight should be able to see the hidden creature and also the creature’s true form (as long as they aren’t behind cover).

This is the correct answer. Through every edition the amulet has beaten any divination magic, of which True Seeing is one.

... No.