What defines a Fey...?

[Sigurd]

I've always thought that there were two characteristics:

1) They derive their power\joy from something on this material plane

This eventually makes them protect the plane against extra-planers etc. It makes them compete with humans etc... and to a lesser extent elves. I think they see Humans as the youngest children of the plane - amusing and controllable.

2) An association with the fey queen

They might be followers or they might be exiles but they have some relation to the Seely or Unseely court. The courts occasionally create fey creatures from other types by their collective magic or some deep universal law. The courts are capricious and cruel - beurocracy on hard drugs.

 

[Ferret]

I go with the conncection to a place/force/idea. No need for them to be just nature spirits.

 

[The Great Bear King]

Here are a few of what I consider Fey

Ogres are Fey with supernatual connections to machanics, freedom, brewing, arcane magic, and swampland. They're usually Chaotic Good.

Elves are Fey with supernatual connections to forests, freedom, plains, the hearth, and arcane magic. They're usually Chaotic Good.

Goblins are Fey with supernatual connections to arcane magic, righteous order, the forge, metalworking, caverns, mines, and stone. They're usually Lawful Good (some of them make human paladins look like libertines).

Orcs are Fey with supernatual connections to fear, blighted plants, rotting oak, slavery, tyranny, war, and arcane magic. They're usually Lawful Evil.

 

[Tonguez]

In the traditional beleifs of my culture there is a dualistic worldview between Spirit and Body with the Psyche/Soul/Mind as a mediator. There is also a distinction made between 'Spirits', Humans and 'other things' (considered spirits but with bodies. these other things generally fit the role of fey (their are dragon-like guardian monsters, a pale humanoid race that lives in the mist etc). Anyway it allows an easier division

Mortals - Flesh-born: These are creatures of flesh and blood though Spirit and Psyche and within them
Outsiders - Spirit-born: These creatures manifest the divine Spirit of the creator as gods and 'divinities'
Fey - Pysche-born: These creatures manifest from the psyche ie the mind, emotions and instincts. Hence they are tied to dreams and usually exhibit some extreme emotional obsession. They are physical but ephemeral. Powerful minds (ie Shaman/Druids) can interact with them and even call them into being (perhaps as guardians, or to serve some other purpose). The old gnarled tree (Dryad?) or the strangely shaped rock may in facy be a guardian if this type...