Sometimes things need to stew a bit. Lucky enough, the OSR delivers enough ingredients and the result keeps tasting different. It's like Carl Weathers says in Arrested Development.
The First Hunt
It all started with an idea about Personal Magic Weapons and a comment by Porky. There was a lot of ideas flying around (check here and here, if interested), but in the end it became rather difficult to give this concepts more form (the basic idea being to use D&D to generate a settings history and with results directly convertible to the main game). Porky called it Noircana.
To stress the analogy a bit further, I sailed the blogosphere some time in the hopes to see this beast show its back again somehow. And then it did...
So Telecanter wrote this interesting piece about villages having hit points with some neat mechanics to make it relevant for the game and the players. And I thought, well, that's the hard part. The rest follows easy enough. Level indicates the size of the settlement (Name Level being "City"), environment is the enemy and main source for xp (which shows in achievements like a mine, a smith, a tavern, etc.). AC defines how well a settlement is fortified, Saves are by class (Elven settlement means Elven Saves, etc.) and before you know it, the players domain fits on a small sheet and the domain game is like playing D&D with another character!
What else? (and another ingredient)
So the environment of a settlement is treated like monsters, more stats aren't needed. You have a forest and a lake? Low AC and enough HD to mine it (lake has no hd anymore = fished empty). A round "fighting" that environment could be a week in the setting (or something like that). Big Players (Monsters, other settlements, etc.) in a region have stats already and I'd give them a territory according to that (like I did here).
With an idea how to fight, there needs to be an idea to resolve the fights in a fitting manner. Don't know if y'all heard of Solo Heroes by Sine Nomine Publishing (here is Tenkar's review), but it provides some nice ideas how to resolve fights with only one character dealing damage like a group of adventurers would (with the hero basically dealing damage to the hd instead of the hp and monsters dealing less damage). As far as I remember it (no access to my PC and thus the pdf right now), it is a perfect fit for this.
The Rules Cyclopedia helps to assign a threat level to the environment*. Let's see. I'll extrapolate a little (don't have my English pdf version available and take what I need from the German physical book I own). It's monster hd (modified by special abilities) divided by group level (maybe multiplied by 5, because of Solo Heroes...). The result gives a percentage indicating how difficult an encounter might be (with 1-10% being to easy and 110%+ being extremely dangerous).
With this ratio we can conclude how dangerous threats near a settlement might be. And if they deal damage by the week, there is enough room for heroes to react on behalf of a town in danger! And with stocking the environment, a DM already knows, which areas are avoided by the townsfolk and where they loot.
Ability Scores might be a bit tricky. CON might give a bonus to hp, so that's more people. CHA indicates retainers, so that could indicate farms and some such near by, DEX gives a bonus to AC, so that could be a local feature protecting the town, STR just gives a bonus to attacks and damage, no problems here, INT could indicate the level of proficiency available in a town (there are fishermen, bonus to fishing, etc.), WIS the general attitude towards strangers (but the last two are more difficult).
I'd go with damage as the hd-die indicates (a d6 in this case) and use Weapon Mastery (sort of), giving one additional die every three levels (so a City, Level 9, would deal (or harvest) 4d6 damage to the environment).
So they start harvesting/fighting the environment and gain xp for that**. Solo Heroes for the win, again. To allow a character in this nifty little game a normal advancement, it gives more xp for encounters (Ten times, maybe? More? I don't know, need to get my hands on the pdf again...). With advancement, they gain better hp, so there are more people living there, harvesting, advancing further, dealing with threats, getting stronger (using more territory) and so on.
Suited for Domain Games
A Fighter achieves Name Level and gets a portion wilderness to take care of. The DM knows what's there. The character builds his Castle and has a Level 1 settlement with a good AC going (with a number of people living there and all that). Maybe the character's Ability Scores even form the settlement, so there are the stats. All is in place and this might be a game within the game already (with different classes forming their settlements differently, etc.).
Karek Thel needs a Harbor
As soon as I have the time, I'll test drive this with the island setting I wrote about this month and give a bit more flesh to those bones (looting some Noircana ideas as I see fit). Ideas and comments are welcome, of course...
*Maybe interesting in and of itself, the RC already included rules to estimate a Challenge Rating as an optional Rule for DMs to produce a more "balanced" game.
**Need to build a new class (Settlement) for that.