Just a little hideaway to discuss the use of old and new D20/OGL books with Fantasy Craft.
I am going to start off with the now out of print (even as PDF) Fantasy Flight City Works, written by Mike Mearls.
I pulled out City Works to start fleshing out my steampunk city Blythe (called Blight by many).
Only the first chapter is D&D specific, leaving pretty much everything else usable, as is.
Chapter One has classes, feats, and spells. Some could be converted without too much difficulty, others, not so much, and some are already covered by the Fantasy Craft rules (largely the Blend skill).
Chapter Two has the basics about creating cities - why the happen, where they tend to happen, and how they are governed. Aside from a few NPCs and rules for bribery and trials everything can be used as is.
Chapter Three is all about designing cities, and is why I pulled out the book. Everything can be used as is. The basic premise breaks down cities into areas (industries, markets high, middle, and lower class residential, docks, warehouses, etc.) and how much of the city each covers. The areas are further broken down into blocks, useful for mapping things out. Each block is 500x500 feet, and represents about 100 people.
As an example - the city I am currently working on:
I have decided that Blythe has a population of about 250,000 people - so it would cover 2500 blocks - if it were square that would be 500 blocks on a side. By D&D terms a pretty massive city!
Because I am going with an industrial age city I arbitrarily decide that they will cram about ten times the number of people and/or industries into each block - tenements will be bigger, occupy a larger percentage of space, confining the streets, and be multiple stories - typically three or four. Factories will occupy much of an Industrial block, cramped sweatshops. Government buildings will reach skywards, or lower disapprovingly at the streets below. So the number of blocks drops down to an easier to map 50 on a side, if square.

Half of the available blocks will be industries, the other half residential.
As a Port city the break down looks like this:
Industries: 125 blocks pre-total
Docks 10% (13 blocks) (The whole point of the town. One dock will have facilities for prison transfers.)
Entertainment 10% (13 blocks) (Including the red light districts)
Government 5% (6 blocks) (The prison would normally be part of this, but instead I am going to make it a special area just outside of the city proper, along one f the canals.)
Industrial 10% (13 blocks) (I may up this to include some big factories.)
Markets 20% (25 blocks)
Military 5% (6 blocks)
Temples 5% (6 blocks) (At last one block will include a fairly massive cathedral - I still plan on running a Gargoyles game in this setting some day!)
Travel 20% (25 blocks) (Because of the setting, I am going to include canals and railroad under this heading.)
Warehouses 15% (19 blocks)
Actual Total 126 Blocks - If I have space I may increase some of these areas; more docks and warehouses for the port!
Residential:125 blocks pre-total
Upper Class 20% (25 blocks)
Middle Class 25% (31 blocks)
Lower Class 60 % (75 blocks)
Slums 10% (13 blocks)
Actual Total 144 Blocks
Looks like the residential areas sprawl a bit, but I know how many map squares I am going to need. For Blight I am dividing the city with a fairly major river, and canals running off of the river.
The chapter then goes into placing the blocks, placing key buildings, placing streets, and building density. Probably my favorite system for creating cities in RPGs.
Chapter Four is about designing city adventures and events, and has a simple chase system. The chase system is fairly compatible with Fantasy Craft, essentially a framework for Complex Actions.
Chapter Five closes off the book with city encounters - aside from one monster table the encounter tables manage to be pretty much system free, making conversion work minimal.
All in all, this book is well worth dusting off for use in Fantasy Craft.
The Auld Grump