How does the Ring of the Darkhidden interact with spells/effects that detect/reveal/dispell invisibility?

Question

The Ring of the Darkhidden is found in the Magic Item Compendium page 122 and says:

You are invisible to darkvision, although you are fully visible in normal light.

How do spells such as See Invisibility, Invisibility Purge, True Seeing, or other such spells/abilities interact with the ring's effect? I'm assuming True Seeing works since it trumps everything illusion, but what about the others? Invisibility works on both vision and darkvision, so is the ring's effect simply discount invisibility or would it count as a different enough effect to bypass spells that only trip on "invisibility"?

Answer 1

Invisibility is a specific status condition, and ring of the darkhidden grants it in a limited form. This is completely reasonable with respect to the definition of invisibility, which defines itself as

Visually undetectable.

and goes on to describe several different types of senses that can detect invisible creatures where “normal vision” cannot. Ring of the darkhidden simply makes you “visually undetectable” with all that entails to those relying on darkvision, but not to normal vision. It’s still the invisibility condition, and thus see invisibility would thwart it.

Note, however, that (as far as I know), no creature with darkvision lacks normal vision. Thus, ring of the darkhidden is only useful in situations where you cannot be seen by normal vision to begin with—i.e. it’s so dark only darkvision works. With ring of the darkhidden, it doesn’t.