Quote Originally Posted by weegee
I've tried looking at those tech maps, but I can't make heads from tails.
Essentially the Tech Tree is based on the "fort/keep/castle/citadel/fortress"

Try and picture the "fort/keep/castle/citadel/fortress" upgrades down the left side and the building upgrades to the right. More specialised buildlings not being available until you have built a "Fortress". All military upgrades are dependent on these upgrades.

Try to think of it this way ... new industry will not set up unless they have better security.

Only exception is Farming / Mining / Horse Breeder. These can develop independent of "fort/keep/castle/citadel/fortress" upgrades.