This one is kind of similar, if you're looking to add more game impacts resulting from happiness/unhappiness: http://steamcommunity.com/sharedfiles/filedetails/?id=75508110 As far as adding new civs in game, it isn't difficult to do, using LUA and the Game.AddPlayer method. There is a hard limit of major civs allowed in the game (22 I think, unless using a DLL that bumps that count up). Never used it before, but it doesn't look complicated. Hmmm.... The "Covert Operations" mod I'm working on now has a mission you can give to one of your operator units to attempt to steal an enemy city. I suppose it wouldn't be too much of a stretch to add the possibility of letting the target city either join the attacker's civ (the original plan) or to create a new civ altogether (assuming there weren't 22 civs already in game, and a few other adjustments to bring the civ up to the current level of the defending civ). Link: https://forums.civfanatics.com/threads/covert-operations-mod-collaboration-thread.625740/ May test that a bit when I get the mod more finished. It is an interesting notion.