This question is a follow up to Point buy/structured system for cooperative 4e campaign building?.
I've found a system that is quite close to what we want/need, but there's a catch: it's for 3e and builds on mechanics that are (obviously) not available in our 4e game. The system is called "Castle and Keep" and is featured in the Advanced Player's Guide from Sword&Sorcery Studios (2004).
A quick run down of the system:
- 4 classes of communities (civilian, military, arcane, religious). Those serve as the "character classes" for your village/city/whatever and define which class skills the community has, as well as reputation and defense stats and the number and list from which feats can be taken.
- 6 ability scores (force, mobility, resilience, learning, awareness, command). Pretty much the full equivalents to a normal character's abilities, some of these are added to other stats (e.g. skill modifiers). Ability generation is a point-buy system with the number of points depending on the size of the community.
- 15 skills (appraise, craft, decipher script, diplomacy, gather information, ..., spellcraft, survival, use magic device). These measure the community's capabilities and proficiencies.
- 22 feats. These are exceptional abilities or possessions of the community (e.g. fertile fields, or heavy fortifications). The feats can have prerequisites and usually grant bonuses to wealth, defenses or skills.
- Level based advancement. Each community has a level based on its population (thus gaining or losing inhabitants changes the community's level), which affects the community similar to how character level affects a normal PC or NPC (granting skill points, feats, bonuses to stats, special abilities). A community can have levels in multiple classes, so the small village with a wizard living in his tower may be "civilian 2/arcane 1" or so.
Now the question is: how can this system be best modified to
- work on a much larger scale (regions and whole nations instead of villages/quarters/cities), and
- work on the base of 4e's mechanics (since I don't really want to throw a heavy dose of 3e into an otherwise pure 4e game)