I bought this book hoping to find resources for gamemasters who want to create societies for their campaigns. i.e. "kingdom building." I already have other historically-oriented resources, but game-oriented resources would be useful, even if they would require adaptation from Pathfinder to my preferred systems. The Book of the River Nations does not have anything like this.
I knew it had resources for ambitious players who want to conquer or administer them.
The Book of the River Nations assumes that the characters are exploring and colonizing empty lands. Without resources for gamemasters who want to create societies for their campaigns, or want to interpret a setting's existing societies for the campaigns, it is ill-suited to ambitious characters conquering or administering existing societies, or to adventures for other characters caught in the middle.
The population sizes and army sizes are both far too low for settled agricultural societies. When William the Bastard invaded England, he took an army of around 10,000 people, and conquered a land of around 1,000,000 people. In the game a colossal army has 2,000 people, and an area as large as England would have around 20,000 people in 132 hexes.
The rules don't account for differing climate, or differing crops, or for the advantages of irrigation in semi-desert, though it costs more to build towns in desert.
The rules don't account for trade routes to the mother country or through the new one.
I have to wonder what emptied these lands: have people never settled there? have people already settled, but been killed by invaders and new diseases?
[3 of 5 Stars!]