Pathfinder book - must have for any GM

http://paizo.com/products/btpy8kgr?Book-of-the-River-Nations-Complete-Players-Reference-for-Kingdom-Building

I've been running Kingmaker and it has some great rules for PCs building their own nations, but the Book of the River Nations is a compiled list of all of those rules in one place and it has a good amount of additional material such as extra events, feats, army spells, new tactics, tons of new buildings, and more options for developing land. Anyways, if you are a GM and your players really enjoy being political, I highly encourage you to at least pick up the pdf and give it a read. The rules are pretty solid. I will say that if you were thinking about running kingmaker, I'd pick this book up and it just supplements the rules.

Anywhoot /endrant.