one thing i like about civ5 more than civ4 is the idea that resources are somewhat limited. however i dont think that civ5 did it right in causing an absolute limit of how many units could be built using x resource. I think a much better way would be that once you have access to the resource you can make use of it... however the more you have the cheaper units/buildings etc reliant on the resource become. in other words it sets off something like supply and demand if you have 1 iron swordsmen are X cost but each additional iron resource lowers the cost of swordsmen by some percentage (say 5% just for the sake of argument) other possibilities would be that each resource allows you to have 1 or 2 in production at a time but does not limit the total amount produced. thus if you have 1 resource you can slowly pump out swordsmen one at a time but if you want 2 cities building at the same time you have to find additional resources. The reason i suggest this is that resources are usually limited by supply flow (how much can be provided on a time to time basis. not absolute amounts (at least not in the short term) this would also make trade much more fluid. the cost of iron may go up as civilizations go to war for example. in fact a civ that has lots of iron can make a good buck providing iron to two warring civs (at the possible cost of diplomacy) I simply think that both civ4 and civ5 have this wrong and this idea would be better in game. course we all have good ideas right... what do you think?