So I've been working on my pet rpg project, and originally I envisioned it as humans only, no elves or dwarves etc... but now that I've gotten to fleshing out the setting, specifically the bestiary/ monster's compendium, there does seem to be a void that needs to be filled by other intelligent races. Yes, there are things like undead, angels, devils, demons and other outsiders, as well as I suppose mythic creatures like dragons, phoenixes, minotaurs, mermaids and sirens, but I'm having a hard time committing to how civilized they should be. Should they have towns and kingdoms? Language and writing? Religions, Gods, cosmology? Should they have character classes, or are those human only structures?
For example Wizardry 6/7/8 (I think a lot about Wiz 7) has clear division between the PC races (Human, Elf, Dwarf, Felpurr, Rawulf, Mook, Faerie), the non-PC spacefaring races (Umpani, T'Rang and Helazoid) and the native races (Ratkin, Munks, Danes, Gorns) but they all have character classes (Alchemist, Psionic, Samurai, Ninja, etc).
Anyway, its a bit of a paradox that even if I want a human-centric game, there is still a need to include nonhuman civilizations, at which point its hard to justify not letting them be PC races, even if they are not standard fantasy trope races (for example Wheel of Time has Ogier, Trollocs, Myrdaal and more exotic stuff like Green Men for example, even if the setting is otherwise overwhelmingly human centric). It makes me understand why Elves and Dwarves are there own classes in the original D&D design (besides the origin in fantasy miniature wargaming) and when even AD&D had different class rulesets for humans vs nonhumans.
Like, let's say my rpg has a Nezumi (rat-men) civilization. So shouldn't Nezumi be a playable character race? But Paladin is one of the character classes in the game (as is Valkyrie) and it doesn't make sense for Nezumi to be Valkyries or Paladins.
Hm. But having wrote that I just figured out the solution for my game. Still implementing it for nonhuman PCs is going to take a lot of nonessential work.