Here is a suggestion. This mod necessitates a prerequisite: Terrain types must be clumped together in large batches. (if anyone is familiar with the independently made Tectonics map type from civ4 then you have an idea of what I thinking of). Here is the main idea: In the early stages of the game most terrain produces things much as they do, grassland gives two food, plains give a food an a hammer etc. The idea in this case is to give a civ the opportunity to specialize in their local terrain. Here is an example, a civilization located in a very hilly area would choose to go the "hill" tech path, which provides increased production/food to hills tiles, certain special units that gain bonuses in hills, cheaper purchases of new tiles if they are hills, and similar. A plains or desert-based civ would get different bonuses, a maritime tech path would also exist. This would exist in conjunction with the Nights Mod's cultural policies tree so that the effects can be cumulative. The core of the idea is that the tech tree would be created in a way that in the early stages of the game forces the player either to choose a given path that gives specific bonuses, or spread its efforts if it dominates many different terrain types. This would give smaller civs in the peripheral areas (deserts or similar) a competing chance in the early game and also make for interesting early choices: Should I expand from my small hill civ down to the grasslands requiring me to tech to make that area productive, or should I stay on high and keep specializing? At a certain point in the tech tree the branches (which can somewhat intermix slightly) merge together in the "early industrial" tech that changes the societies means of production, in effect nullifying the differences, creating the possibility for large imperialist nations of the industrial age.