I had an idea knocking around inside my head, and then I saw that Dan had already done it over on Throne Of Salt, which rather undercut my brilliant originality.
More time has passed, so I figured I'd have a crack at the idea myself.
So. Demihumans (elf, half-elf, hobbit, dwarf, orc, half-orc, goblin, hob-goblin, dragon). Rather than positing each as a seperate species - and then getting our skull-callipers out to compare them - we'll just look at the position each occupies in our setting socially, and extrapolite backwards from that.
EG, let's suppose you're an elf because you do elf things and people treat you like an elf. But you're still recognisably an elf. What would that look like? How do you get that in society?
Suffice to say, this is all a thought experiment. I have no idea how this would play out in a proper setting or actual game.
Elves
"This person has autism, but their knowledge or power means we have to treat them respectfully."
An elf is quite possibly smarter than you, but (if you aren't also an elf) the ways they think don't make sense. They follow patterns and customs that most people don't, they prioritise things regular people don't, they just fucking know things sometimes. Sometimes unusually innocent, sometimes deeply worldly and old before their time.
Elves typically go into professions where knowledge is important, and people can't just reject you out of hand for being unearthly and weird. Mages, priests, artists, nuns, midwives. That air of oddness can be a perk; it lets people know they're dealing with an elf, and should be prepared to act accordingly.
You treat elves with respect. After all, they know things and they have sufficient power or clout that if you offend them, they can make you regret it.
Most have at least a smattering of magic, some handy utility powers and maybe something like a magic missile to smack people who don't show respect. They take to it naturally, and often don't get that others can't just learn magic with the same fluency and focus that they do. Isn't it easy?
It doesn't have to be autism, but that's the most common one, and also the one the author has and is familiar with.
Different types of elves correspond to areas of focus. Wood elves like the natural earthy things like birds and trees, high elves like some 'respectable' topic like history or heraldry, dark elves know about something vaguelly taboo like poisons or spiders.
The term 'half-elf' is basically the same as 'high functioning'. Not really used by elves among themselves, but regular people use it to describe elves that seem more normal and approachable.
Generally, elf-ness is broadly hereditable, about as hereditable as autistic traits in the real world. A changeling is just somebody who turns out to be an elf despite nobody expecting it based on their family.
Elf communities exist. Cloisters and hideaways. They get weird fast.
Dwarves
"From a commoner family that knows marvelous trade secrets."
Being a dwarf means you've inherited the family name (or been adopted or married into it). You're one of a particular clan, and your clan knows how to do something that they guard jealously.
Metalworking is a common one. Mining and underground construction techniques are another. Warfare with specific secret techniques is another. Maybe a mix. Whatever it is, your clan has a secret way of doing things that gives you an advantage. Dwarf-made armour is just better than everybody else's. Dwarves who go to war fight in ways that seem impossible to replicate without their lengthy training, and are shockingly effective.
Dwarves often have magic of their own. More secrets handed down the clan. They have their own little sects of the mainstream religions, and their own priests.
The techniques of the dwarves give them an edge over other people. They're just commoners, but they can negotiate with nobles and even royalty, because if the dwarves aren't paid to their satisfaction nobody else can do it as well. And, really, a noble who's jewellery isn't made by dwarves is an embarassment.
These secrets need to be kept, or the dwarves lose their wealth and power. Dwarves prefer to live away from outsiders, in innaccessable places like mountain villages or underground fortresses. They don't trust non-dwarves, who might try to steal their secrets. The exception is other dwarves, who have a vested interest in preserving dwarvish independence.
They know how to hold a grudge. When you're jumped-up commoners bargaining with nobility, you have to.
Hobbits
"These people have fucked off to live independently, and its too much effort to get them to come back."
Hobbits have opted out of mainstream society to go and do something else. Maybe they dig holes in hillsides and make a commune that lives in a rural idyl. Maybe they have a caravan and travel the world with like-minded hobbits, trading goods and stories. Maybe they flee from persecution and live in floating villages hidden in the marshes.
Basically, they're hippies. They rejected the rat race and went to live some more authentic, satisfying or reasonable life off in the middle of nowhere. Their communities are tight-knit, idealistic and egaletarian, mostly. When a hobbit community goes wrong, it goes really wrong really quickly, and then falls apart entirely.
Some people are first-generation hobbits, who - alongside a group of like-minded individuals - chose to live like this. Some were born into a hobbit community and decided to stay. Some found a hobbit community and got adopted into it.
They love their pipeweed, and they're good at hiding. Hobbits get on with dwarves a lot of the time, even if their relationships tend to be distant.
The author has dated a number of hobbits in her time.
When some horrible dark lord rises up, fueled by the fire and smoke of industry and averice, and starts building dreadful armies and dark satanic mills, hobbits tend to be among the first victims they go after. Them and other minorities. Hobbits don't tend to fight back in an organised way, they go to ground, move on, or form guerilla resistance movements.
They are probably living happier lives than you are. Why aren't you a hobbit, actually?
Orcs
"Soldiers without homes."
Being an orc means fighting as a way of living. No farms, towns, shrines, capitals. Just a military camp that moves as the campaign moves. War is all you know. Home isn't a real concept, or isn't anymore, you just live wherever the fighting is, or wherever you go the fighting follows.
Some orcs are mercenaries. Poverty or desperation or persecution pushes them to sign up with a mercenary band. A tent in a military camp is still a roof over your head, sort of. Sometimes the orc is fleeing something, or ambitious.
Maybe they don't intend to be an orc for long. Really, though, cashing out isn't likely to happen. You die young, or if you don't your so scarred - emotionally and physically - that regular society doesn't want you back.
Other orcs didn't have a home to begin with. An invasion took it from you, and now your home is occupied by somebody else. Or your home has been on the front-lines of a trench war for decades and completely fucking uninhabitable, and the conflict is all you know.
Orcs stick together. Their real loyalty is to their comrades. An employer has their loyalty only as much as they pay them, unless that employer is also an orc.
There's a code. They treat orcs on the other side of the conflict better than the rest of the enemy. If you capture an enemy orc, he's one of yours now. He switches sides. Maybe his whole band surrenders and joins you, and they're with you now. Their loyalty is to the orcs, not to whichever kings and emperors started this war to begin with.
Sometimes orcs end up in the armies of dark lords. This lasts as long as the dark lord keeps paying them and doesn't expect them to break the code. They don't care what fucked up stuff the dark lord is doing, spend long enough as a mercenary and you get numb to attrocities, so long as the money keeps coming.
Other orcs take a more direct approach, and support themselves through banditry and conquest.
There's a lot of overlap between orcs and goblins. There's surprising overlap between orcs and dwarves.
Goblins
"Sentient vermin."
Even worse than being an orc. Somebody in power wants you gone, and now you don't have rights anymore. Basically outlaws.
A goblin might be a heretic, a criminal, somebody whose land got stolen, a fugitive, or something like that. Or just born to goblin parents. You're not part of regular society, and regular society wants you fucking gone. There's overlap between goblins and orcs. People don't like to admit it, but there's overlap between goblins and hobbits.
There's absolutely no social safety net when you're a goblin. Individual people might be nice to you, but others won't be, and maybe there's a bounty on your head again. Best to hide from them, then.
Goblins get really, really good at hiding. They find places they can escape from the world, and they band together with other goblins. When society is your enemy, fuck 'em. Feed yourself through subtle theft, banditry, whatever it takes. Trust your fellow goblins to keep you safe. If regular folks look at you funny, kick their teeth in so they won't want to chase after you in a hurry, and go to ground. Fill your home with cunning traps. Fuck 'em, look out for your own.
The world wants you dead, but you're clawing and spitting and snarling and still alive.
Hobgoblins are when these outlaws arm themselves and actively fight back. Guerillas, terrorists, militias, what have you. They cobble together uniforms, and stick the heads of those who'd oppress or exterminate them on spikes before fading back into the shadows. They're probably also orcs.
Kobolds are when these outlaws are also dwarves, and have secret knowledge that mean you have to take them seriously, even while trying hard to get rid of them. Kobolds tend to be very good at building impregnable fortresses full of traps.
Dragons
"Personally strong enough to do whatever the fuck they want with no consequences."
The rule of thumb is this: if you can walk into an average town by yourself and demand they give you tribute, and get it without any noteworthy resistance, you're a dragon.
You probably weren't a building-sized fire-breathing carnivorous flying lizard to begin with. But once you hit a certain level of power, you realise nothing's stopping you from turning into one if you want to, and there never was.
Dragons shapeshift. They look like people, until they don't. Every one is a legend. Every one is unique.
Kings aren't dragons. Their power comes from systems of laws and heirarchy and custom meaning people choose to follow them. Wizards might be, as might particularly mighty warriors. Subtlety and subterfuge aren't particularly inclined towards making you a dragon, normally, but often somebody who excels in those areas will - when their back is to the wall - reveal that they were a dragon all along.
If you can personally reduce anybody who speaks back to you to two whisps of smoke coming from a pair of shoes (or a red smear), you're a dragon.
Some dragons do their best not to act like dragons. They try to be benevolent, to blend in with society, to only flex their power in emergencies. The rest - the majority, even - are problems.
A typical dragon ensures those who follow them are loyal by making dramatic examples. They tend to enjoy skull fortresses, big piles of treasure, and appending titles like 'the terrible' onto their name.
People who set out to slay dragons generally fail. Those who succeed normally become dragons themselves.
Elves become dragons disproportionately often. It's the focus that does it. They're often the most reasonable dragons.
Orcs do too. We call them black dragons, and they burn bright and furious, leading a horde of orcs behind them until they inevitably perish doing something exciting.
Goblins also produce a lot of dragons, particularly kobolds. A goblin who becomes a dragon is really good news (for the goblins and hobgoblins and kobolds and orcs of the world) and really bad news (for the sort of people who decided you were a goblin in the first place). These get called red dragons, because of all the blood that they leave behind.
Red dragons tend not to be inclined to be merciful to their enemies. Their followers, on the other hand, often do pretty well for themselves. When you have a red dragon on your side, you might not have to be a goblin for long.
Very successful kingdoms have been founded by a red dragon with a big dream.