First up is The City. I'm also currently working on a D&D 4th ed. campaign, and considering starting work on a Mongoose Traveller campaign and a Lamentations of the Flame Princess campaign. And maybe an OD&D megadungeon somewhere in the future.
But first The City. The city is really just supposed to be setting for testing out the Fantasy Craft rules.
The City has a name, but to the inhabitants it is known simply as "The City". It is the heart and capital of an empire, but the empire is in decline. The current emperor has lost all interest in the city, and occupy himself with his capital and his foreign campaigns. No single power really controls the city, and unified law enforcement is non-existent. The city is a warren of feuding noble clans, struggling guilds, gangs, and people just trying to survive. What "law enforcement" does exist is locally organized, and the law they enforce is formulated by their employers, whether they be guards of the nobles, watchmen of the guilds, or simply a militia raised to protect a neighborhood.
The starting idea was purely for the place to be a quick testing ground, where I could make an adventure around The Alexandrian's idea of node-based design.
I spent an evening with City Works from Fantasy Flight Games, and made the following rough map of the city's neighborhoods.
City Works work with city blocks that are approximately 500 ft on a side, with 100 inhabitants. So this city has approximately 80.000 inhabitants, and is some three miles across. The colors denote the type of district.
But then I got side-tracked. I'm now thinking on a setting that might work for an extended campaign. Not because I'm necessarily going to run an extended campaign, but because I liked the ideas I got. Mostly I'm thinking larger. Much larger.
The empire is in decline. When it was at its height, the population numbered in untold millions. Now large parts of the city is abandoned and in ruins due to plagues, fires or other incidents. One can walk for hours and even days to reach the inner parts of the ruined areas. Goblins, undead, vile cults and other enemies of man lurk in ruins.
So, I'm starting the map from scratch. For this city I'm going to work with a larger scale. I wanted those big ruin areas with multi-hour walks. So I decided to first start by constructing the city from megablocks, which would contain multiple city works blocks. After some calculations, I decided that I would go with megablocks that were 25 city blocks wide on each side (2.4 miles wide, and with a population of 62500 each). Currently I'm thinking I'll have 1600 of these megablocks, for a total theoretical population of 1 billion inhabitants when the city was at its height. I guess that counts as untold millions, though the goal here is the city's size, not its population.
To spread out the districts a bit (City Works wants all the government districts to lie in the city center for example) I'm going to construct the city as three cities that grew together, two of 500 megablocks, and one of 600 megablocks.
This is the basic map I'll be working from. We got a river running down the center, and tall ridges rising on either side. The red lines are city walls. Most of the interior walls will be in some state of decay, and passages broken through in many places, but they will still serve to split up the districts once I get around to placing those.