I am an RPG ultra-naturalist, for good or ill. The good part is that I do enjoy a lot thinking on how a determinate civilization or animal has adapted to its circumstances, and that usually sends me on a spiral with each decision revealing me more about their circumstances and about them. It also has a payoff in the sporadic cases in which players do decide to investigate more and get involved with something I have actually paid attention to (last week they spend the whole session up and down a tribe of Pink Slimes, it was incidentally one of the best sessions in a lot of time)
On the bad side, I'm completelly blocked when I roll a random encounter of 4 goblins, because I do not understand any version of goblin culture and views, and I end up making them Saturday Morning Mooks with little to offer after their death. Then I start to think: Why were this goblins attacking PCs? Are they hungry? are they greedy? what do they need gold for? Where they live? Do they have a home? Where are the goblin girls? Why do they chose to live in a humid rock passage waiting for the year an adventurer passes by?
My setting might be a little atypical for your classic D&D game. It features mostly Trow (which are humans by another name, not related to Drow at any degree) and Kobolds (Just halflings); Orcs as the everpresent foreign raiders, and very occasional Dryads and Nixes. The tone I usually keep is knights and castles more than anything, 20% dungeons, 80% wilderness and city play. I describe the armors and weapons as eastern-european, but in my mind, the framework is japanese, and the characters under the plate armor disguise are taken from Usagi Yojimbo and Kurosawa movies (which is what I am more in touch with, and seems to flow better from me)
I don't have subterranean humanoid civilizations in my setting, because I find flaws in all of them. Not in their essence (sometimes a goblin is OK! I don't say that they are not workable in another game) but in the relationship with the tone and idiosincrasy of the current campaign.
Lets break it case by case with pros and cons:
John Goblin from Nekrogoblikon
GOBLINS
+ They make good cannon fodder: You can drop them by lots, and make up for classic skirmish battles.
+ They range from murky to evil, is easy for me to put them as enemies without much questioning.
- They are very shallow. I cannot imagine a goblin settlement without it being an humoristic take. Their motives to live are trifling: you can either make them psychopaths who kill for pleasure, or greedy fuckers crave for gold, but neither of them sustains goblins as full fleshed out civilization. In the first case, I prefer to potray it through demonic beings, be it immaterial, material or through possesion. The second can work, but still makes one wonder what do goblins do with the other 99% of the time.
DWARVES
+ They craft nice things and explain a lot of magic items found underground.
+ They dig and store jewels and I love jewels in my games. Jewels everywhere make the game feel lush and pretty.
+ Their gold/jewels obsession is very gameable, specially in OSR games, with actually having a behavior that plays into it (mining and adventuring)
+ They dig dungeon passages, thus building interesting passages beyond crypts, grottos and mud tunnels
+ They are good fighters and wear actual armor and weapons, which makes them more challenging as enemies.
+ They normally have good vision in the dark, but not infravision. which breaks the game.
+ They can be easily reasoned with. Their motifs can be strange but comprehensible and any normal human player can understand their morality.
- Their concept is ridiculous, they are just scottish men but smaller. There is exactly one (1) dwarf PC that is repeated through decades of gaming, which is basically Gimli but maybe changing the weapon.
- Dwarven civilization consists in drinking beer, which they somehow make underground? no sense
- No restrictions nor penalty to sunlight, yet they prefer to live in their dark holes because reasons.
- LOTR failed to describe dwarven daily city life, and I cannot imagine one properly that suits the shown character of its dwarves. And nobody has ever attempted to make an interesting take on dwarves after that. It's always beards, axes, beer and end up being humoristic relief. You can fill the gaps making them more "human" but at that point they are just a warrior race's caricature.
DROW
+ They have hot women (or at least as I imagine them) and both genders are somehow aesthetically attractive in all senses, which for me is +++
+ I love that they worship a spider goddess, which makes a lot of sense in the depths; and all the symbiosis they have with spiders (silk garments, cobweb tools, poisoned weapons, spiders as guardians, pets, familiars, magical inspiration, etc)
+ In general, they are described to be more adapted to the underdark (TM) than the also subterranean dwarves, who are more associated to technology and less associated to fungi, luminiscent scarabs and eating scholopendras.
+ Easy to use as enemies, be it for Lolth fundamentalism or because they are just stupid assholes.
+ They are mythologically accurate to the norse myths if we take svartalfar and dokkalfar to be the earliest recorded description of dwarves.
+ Getting penalties on sunlight is something I expect from a subterranean race. There must be a reason they are subterranean after all, or else the whole thing falls apart.
+ They are slavers. This is very interesting to me in many aspects: the gamist (PCs are not always killed on a defeat, but kept as slaves), and opens a lot of opportunities in the building of world stuff and.in "random things and people you find in dungeons".
- Their crazy society is so much over the top that is hard to take seriously. I love when the goth barista at Starbucks spits in my coffee just as much as anybody, but this is just another level. The whole of the society being run by force of dominatrix and survival of the fittest... lol.
- Infravision is just too potent for my taste, in PCs and any other civilized race that can take advantage of it.
And now, what could happen if I took all the things I liked from those three, and put it on a single race instead? As a name, I've chosen something that has no clear ties to any of the three, as so the players have no broken expectations: Nibelungs, as the earth dwellers in the old germanic myth; which, if wikipedia is to be trusted, means "those who live in the mist/clouds"... well. Let's see if we can use that too.
So, nibelungs must be...
...good cannon fodder. An encounter with nibelungs should be at least on par with any other fighter, and they use proper armor and weapons. Those might be crafted with strange underworld means but they are refined and not crude. Their elite troops will possibly use envenomed blades or whips. Their morale is also on par with human bandits: not cowardish, but not temerary either and enjoy combat.
...prone to conflict. Be it for treasure, territory, slave hunt, joy, the demands of their underworld gods, or any other motif we devise through this lines, they have plenty of reasons to attack when the reaction roll goes badly. On the other hand, their morality is not as devious as drow or goblins in general, and at least some of them should be more sensible to provide the opportunity of meaningful interactions (as they will be the only humanoids down in the depths)
... crafters. They are responsible of any architecture found beyond the line where humans do not dare to dig. They can be behind specially rare magical or precious items. Their constructions involve metals, but also all kinds of weird stuff such as spidersilk, insect parts, poisons, fungi, luminiscent stuff, fangs, reptile skin or others.
... hoarder and greedy: at least some of them. Fond of gold and jewels. Maybe miners to some extent at least, but halflings already cover that role. If I get too crazy, I could keep gnomes as a non-playable race just to do this shit and inject cash into the world.
...very good sighted in the dark, but cannot see in total darkness. Correspondingly, they suffer penalties or ills when exposed to sunlight.
...lithe and graceful. Women are invariabily hot and some of them become sorcerer-priestesses, which is a high social position. Their skin being black and hair white can be a trend but not a limitation.
...roguish fighters. Heavy armors are banned to them, and also two handed weapons: I don't want them to be as strong as humans at all. Heavy axes are forbidden. Probably short swords and daggers are their best choice, but will leave this for latter and pay attention to my feelings.
...bound to mist and clouds. As they are weakened by the sun, they prefer to make incursions on the surface on misty or overcast days. This is why the other races have put that name on them. :/
Now, can this make for something that can be explored in a game? This is something for a latter entry, hopefully after I have actually used them.
Inverting colors turns many people into Drow