Probably done before, but I'm thinking about a particular campaign world here, one that I'd love to use once.
Basically, there's this world where all fairytales take place, and it's largely covered in forest and tiny little cosy villages. But hey, evolution happens everywhere, right? Things change. The amount of humans grows expansively, and humans are greedy, powerhungry.
The humans try to gain power by abusing the fairytales (Individually though, not as a group. The humans in this campaign world aren't very united). Some grow insanely powerfull because of this, and off course abuse their power, but none ever grow powerfull enough not to be knocked down at some point by another powerhungry fiend.
As the humans darken, so do the fairytales. The numbers of fairytale monster grow, while the cute little creatures so common in them become slaves to humans as the forest they live in dissapears and gets replaced with cities.
Eventually, the whole world is covered in one big city, even the oceans. It's still a medieval society, but they have made some advancements, such as blundarbusses and such. In daylight, the world is ruled by rich merchants and their greed, while by night the monsters come out of their hiding palces and tear up whomever is still on the streets. Below the houses lie incountable layers of older houses, which were simply built over, and in these dark abandoned places, lurk the most horrible creatures.
To make matters worse, cults have begun springing up, gatherings of the powerhungry, trying to ascend to power in different ways. there are those that trade in one of their senses to sharpen all others, making them very dangerous indeed. Others worship demons, trying to make them help them. Some find strenght in cannibalism, eating other humans to absorb their power. Eating monsters sometimes even. There's a cult that believes in the power of the carnal, a cult that worships mirrors and one that calls upon the ancient power of tarot.
And even though this world is so very dangerous, the city has no authority. None at all. This doesn't mean that it's a democracy. No, there is simply no-one bothering to govern the city, or any significant part of it. This means no laws, no police force, no taxes, no help for the needy. Sure, sometimes the people all lash out together at a murdered, hanging him without trail, and sometimes rich merchants decide they should help out the poor a bit by having food handed out, but none of these are certainties.
There are small centres of good forces though. Universities, spread throughout the world. These make money by researching and selling their finds to the rich. With this money, they have managed to establish a small armed force, called the Nightwatch, who patrol near the university at night. When you feel you're being stalked, you'd better hope you're somewhere near a university. The Nightwatch keeps monsters at bay and governs some rudementary form of law, but they can't handle all the darkness by themselves by far.
That is why there are roaming bands of Whackers. Brutish men, moving from town to town, extinguishing monsters for coin and beer. Whackers are very liked, despite their high prices and extraordinarily bad manners. If they come by, they can clear a district of monsters for a while. Their methods are crude though, to say the least. Wel, basically they just whack stuff with a club, hence whackers.
This huge city is a terrible maze, as you can imagine, and has never been charted completely. To this end, some universities have employed Cartographers, men who travel the world, trying to map it.
There is no magic on this world, despite all the magic creatures running around. Sure, magic powers can be gained, but there is no such thing as actual wizards or sorcerors. The closest thing to that class are Alchemists, striving for the three basic goals of alchemy: transforming matter, achieving eternal life, and creating the homonculus. Basically they just make bombs and potions though, and study lore.
Other people who study lore are Scholars, who work in the university and who know a lot more of it than mere alchemists, and Bards, who travel the world telling tales and seducing women. Bards are a lot like jesters in this campaign world. They can throw knives, breathe fire, do cardtricks and more stuff like that. They also don't play the lute in this world, but a drum or banjo.
A last class would be the travelling barbers. Now, these aren't just barbers, they basically serve as doctors, dentists and surgeons as well. And they can do quite a bit of damage with a cleaver.
Examples of monsters in this campaign world: Grues, Ghouls, Ogres (The I'm gonna grind your bones into my bread kind), Trolls (Made out of stone, lurking under bridges), Redcaps (Mean bloodthirsty garden gnomes who die their pointy hats in their victim's blood), the Big Bad wolf, and so on.
Suggestions, comments, and statting of monsters, classes or anything else is welcome. Just to be clear, player races are all humans or fairy tale races. No D&D elves and dwarves and such.
