Suggestions for a map of kingdoms:
rivers random flooding, affects crop production plus army manoeuvres
woodlands, type, affects worker's lives (keeping warm in winter and cooking) and construction rates
arable land, quality affects cropping levels (bog/good soil/dessert) & (post flooding giving silt deposits)
mountains which affect gold mining (land slides - destroy mines or expose veins)
(All done with a random number generator) and really simple graphics.
Poor villages or aggressive clans men could migrate to other (fixed) sites with various penalties depending on weather, terrain and passing of other villages.
What doest thou think?