Explore the Uncharted! Tame the Land! Rule Your Own Nation! The Book of the River Nations: Complete Player's Reference to Kingdom Building organizes all the rules players (and GMs) need to explore new lands, build nations, and defend against invading armies consolidated into one easy to reference tome. Starting with rules included in the Kingmaker Adventure Path, this Pathfinder-compatible sourcebook expands upon every aspect of kingdom building and mass combat, and delivers new feats, spells, and class options to give PCs the edge in conquering and ruling their own corner of the world.