I recently got onto the indie game "Girls like robots" where a series of different tiles need to be arranged in order to maximise the beneficial connections between them according to relatively simple rules for each type. It is the perfect example of a simple mechanic that gives deep game play. The only comparable examples I think of in ciV are a few unique improvements like moai, terrace farms and chateaus and I find these add an fair amount of fun to optimise their placement. Should something like this be considered in the mod where all possible tile improvements have positive and negative effects on other tile improvements? Currently there are very few tiles that make you seriously think about what to put on them. The only issues are which ones to improve first (critical in the early game) and where to situate a city. Once you have specialised your city/civ toward a particular improvement further improvements become a no brainer. It has realism on its side- trading posts on a road should give more gold, farms surrounded by mines should be less healthy and give less food, etc. If balanced well it would also give a dynamic tension between specialising a city (to maximise building based improvement bonuses) and maximising positive relations between different improvement types.