I've spent my free time this week working up Dokkaebi (Korean goblin), Koropokuru (Ainu dwarf), Shenseng (Pan-Asian spirit folk) and Vanara (Indian monkey-men) as classes for TSR-East.
Mostly I'm satisfied. The koropokuru is mostly a fighter variant, but has a few special abilities, similar to the way the dwarf and halfling classes do in normal Classic D&D. Shenseng are spellcasters, but may be clerical or magical depending on spirit type (forest, mountain, river, or desert). Vanara are just a variant of my new (Flying Swordsmen inspired) Martial Artist class, with some unique martial arts abilities. I think these are all playable and fill niches in the game.
The dokkaebi class, however, I'm not so keen on. I started out making it another fighter variant, but since Nate is playing a dokkaebi shaman, and in legends they have magical powers, I gave them spell-like abilities instead of most Fighter abilities. While this may fill a niche (slightly better at fighting than a Cleric...but not a lot, and able to fill some Cleric duties but not a lot), the Forest and River Shenseng also fill this niche, although a bit more clerical than fightery.
Since the dokkaebi is the class with redundant purpose and novel mechanics that haven't been tried before (by me), I'm thinking to revise or scrap it.
I could go with just three demi-humans. But I would like something definitely Korean in origin. I've been living here 13 years, am going to be living here a lot longer, might as well give Korean legends and myths some love. The problem is, Korea doesn't have a lot of original mythical creatures, and most of the ones it has probably aren't appropriate for PCs in an RPG of dungeon delving and treasure accumulation.
So, make the dokkaebi class more like the Fighter? Or find something that might fill in a pseudo Thief slot? The koropokuru class has a bit of Rangery ability, with better surprise, hearing, dwarf-style trap detection, and infravision, so they can make good scouts in dungeons or wilderness.
If I want a more thief/ninja type demi-human, though, there aren't a lot of good candidates with Korean flavor. Bears and tigers are important in Korean mythology, but anthropomorphized bears and tigers seem like variant fighters to me, so I might as well stick with the Dokkaebi. Or maybe I should stop thinking about Nate's character (I won't be switching my West Marches game to these rules) and make the Dokkaebi more of a bruiser and less of a support caster type.