Hag (and changeling) detection?

[Douglas Muir 406]

1) Is there any canonical way to detect a hag?

2) Is there any canonical way to detect a changeling?

3) If the answer to the first two questions is "no", then a spell, ritual or magic item would be needed to detect hags and changelings. What might such a spell, ritual or item look like -- level, cost, and so forth?

Thanks in advance,

Doug M.

[Renata Maclean]

Changelings don't actually have any racial illusion or shapechanging abilities, despite their name and heritage, so detecting them should be comparable to other demi-humans
I'm not sure of any specific way to detect hags, compounded by the issue that (Hag) is not actually a subtype, and not all hags are monstrous humanoids.
True Seeing would obviously work, although by the point that spell becomes easily available, most hags probably are not a significant threat

[LoudKid]

I think a 1st level "Detect (Witchcraft or Witches)" spell that apes the rules of the other 1st level "Detect" spells would be reasonable.

Other than homebrewing that, I think Hags are all evil by default, so Detect Evil works for them.

[Lathiira]

If the hag is in disguise, a successful opposed roll of Perception vs. her Disguise skill should help, though that might only get you to the point of 'this person isn't what they seem'.

[Aksess]

Sorry for necrothreading, but I've just come across this problem for a character, and despite this thread having exactly the right questions, it doesn't really have answers.

How do commoners/adventuring parties detect other demi-humans?
If a changeling child is left with a commoner family, the DC to identify something is 10 + CR, right? So maybe a knowledge (nature) DC 11? The commoner family has a decent chance of recognizing the changeling.

However, that means that as a changeling acquires class levels, she gets harder to identify simply because her CR is higher.
A changeling child isn't in disguise, since no disguise check was made.

But there is no DC to identify a dwarf, people just know what dwarves are.

What are the consequences of someone passing the Knowledge (nature)/perception check? Lathiira suggested a good open-ended option that I like, that just suggests that this person isn't exclusively human. If the party met an NPC who appeared human, they probably wouldn't get suspicious and wouldn't attempt to roll a knowledge (nature) check to see if that NPC is demi-human. So I suppose that the act of rolling a knowledge (nature) is the same as being suspicous of someone.

[Val'bryn2]

The DC doesn't go up based on class level. The DC to identify a dwarf would be knowledge local DC 5, since it has no hd, or 6 if you count it as 1 HD. A changeling, as a more obscure race, would be Local DC 10 or 11. If 11, you can only identify it if you have a rank in knowledge local, or else can use it untrained.