I am not modding now, but was browsing around. I have not played Civ 4 for ages. I am way to busy in school right now to mod. I do have a background in Anthropology and Geography if that means anything. My suggestion would be culture should be linked to technology. Making resources is a technology. Corn was developed in stages for example. Here is what I was thinking if interested. This is a modification I was planning to work on before. Civilization Specific Tech Trees http://forums.civfanatics.com/showthread.php?t=275046 I was thinking alternate tech trees per era. For example lets say a Mesoamerican alternate history. Code: Homo sapiens sapiens Acheulean-----(some tech) Eastern Migrations Levallois-----(some tech) South Americas Magdalenian-----(some tech) Olmec(Mexico) Neolithic-----Beginnings of Corn Domestication Different techs for producing different resources or particular increased production of a type of food. That was the idea anyway. Now how to go about it well I am forgetting at the moment. I was just thinking leaders decided your culture group if you are needing further specifics within a group, and perhaps the player could decide from a limited amount of choices based on what type tech trees that are in. I was also thinking UU's and UB's being entirely separate. Basically that every civ has access to them but need specific techs to unlock them. I had in mind to make dead end techs for UUs and UBs and different ones per an unique tech tree of an era. For example a Neolithic Mesoamerican tech tree would have some choices as in what unique units they would get from the era specific tech tree, and once chosen the other unique units in that particular era specific tech tree would not be available. So they would be some overlap in some cases of unique units and buildings. Yes it would be a lot of work, and in the cases of techs spanning across multiple alternative tech trees I would just duplicate the tech with a new name. Anyway if I am not making any sense I can break it down it more details. If you don't really care then oh well I am sorry for posting. I only check the forums every once in a while to see what is going on in the civ community. So if you want a response from me probably better to email me or send a pm.