Recently I've been planning a new campaign, which, if everything goes according to plan should start next month. I've been giving some thought to how to implement faeries in my campaign and I have a few ideas that I want to see what you're opinion on is.
One thing is that I've been looking for an opportunity to use Rob Kuntz's Dungeon Sets that I purchased a while ago. I was recently looking them over and thought about the "dome" in which the first level is inside of. Fey are often associated with hills and mounds right? So I was thinking that this dungeon should be primarily inhabited by Fey. But I'm not sure exactly how populous the Fey should be. It doesn't seem that there should be hordes of Fey, however weak so close to the surface. Perhaps in the lower levels, where the connection to the shadowy realm where they come from (since these are evil fey) is stronger there might be large numbers but there should probably be only a few in the upper area.
I'm also considering having this dungeon be home to a cult devoted to the primordial, chthonic gods of the Elves. Would it be appropriate for these gods to be associated with the fey? I'm seeing it as being like the Tuatha Dé Danann being considered in later times to be Faeries.
I've also been considering how to stat Faeries in my campaign. Faeries are quite diverse. There are many stories about many kinds of Faeries. Yet there are some general kinds. So I'm thinking of coming up with some base stats for various types and then modifying them, applying templates for the desired result. Here's the kinds I've come up with:
Sidhe (may be under the banner of Elves)
Sprites (Two base stats, diminutive and tiny, or perhaps just tiny and then apply the "Young" simple template. May also include some small creatures like Gnomes, but I'm thinking the Fey Gnomes might be tiny, unlike they're mortal (and playable) descendants, and I'm also not sure that gnomes should be sprites, and perhaps they should have they're own category, along with similar creatures like Brownies, Lepreacauns, ect.)
Ogre/Troll (also Fomors, Oni, Ghuls, Rakshas, ect, I'm not sure whether these should all be big creatures, or there might be some room for smaller trolls, there might be some overlap with the Bogie category)
Nature Spirits (Nymphs, Fossergrims, ect. as well as some elemental creatures, in fact I'm considering using elementals as the baseline creature in this case, dwarves may be descended from Earth-based Nature Spirits)
Animalfolk (these won't have one set of base stats, but rather be modified versions of the animals in question, includes the Japanese Hengeyokai and maybe Lycanthropes)
Bogie (Small, ugly, evil fey, goblins (though that name may also apply to orcs, I'm considering having the mortal goblinoids descended from the fey), boggards, ect.)
Elves (Again there's mortal elves, the sylvan and high and also a fey version, which again may be associated with the Sidhe. There's also the Eladrin, not technically Fey but Celestials (then again there maybe some overlap), which I'm associating with the Light Elves of Norse Mythology. I'm considering having Drow be the same thing, fiendish elves)
Something I've noticed in my research on Fey is that because Fey can mean so many things and are theorized to have so many different origins (fallen angels, elements, the dead, old gods) Fey might not be such a useful term. Perhaps the word "Fairy" is just used by the common folk to describe many different and diseparate supernatural creatures. Sure there are the winged Sprites that fit the common image of Fairies, but beyond that there are many other things associated with them that might not actually be related. Maybe demons and elementals and gods associate with Faeries and so are often confused with them.