This is something that I have been pondering on since Civ V came out. What about the inclusion of disease as something players have to deal with during the growth of their empire? I was initially going to plan a mod around this but my ideas far exceed my modding knowledge so I thought I would throw it out as an idea. I made a list of Civs (excluding DLC civs) and then researched diseases or famines that each of them dealt with during their reigns. Every civ in the game has had to deal with at least the plague or something similar so it seemed like something that could be implemented and still be somewhat historically accurate. Basically my idea was that at the start of the game each civ started with the potential to be inflicted by a disease or famine that relates to what they suffered through historically. The player then has to maintain and manage their cities pop and food supplies to prevent from being affected. In the case of the plague, if a civ let their food supplies drop to starving through poor management, they would then have a set number of turns to get out of this state before being affected. This "plague" debuff would impact the growth of pop and then eventually kill citizens. For example, if affected by the plague, 1 citizen is killed every 10 turns. This could also affect a city in other ways, for example any military units constructed during a plague era would have reduced stats (indicated by a plague icon above the units head). Also if you garrisoned this unit in another city there is a chance that the city may also become affected by plague (proliferation of the disease). Military units affected by this could cure themselves by waiting a certain number of turns within friendly territory that isn't afflicted by plague. I also considered the threat this could impose on other civs. For example if Civ 1 has military units inflicted with plague and engages in combat with Civ 2. Then Civ 2's own military units could become infected. Likewise, if Civ 1 could send infected military units into Civ 2's territory (during wartime) and if this infected unit lasted a certain number of turns within enemy territory, then Civ 2's nearest city would become infected. In this scenario, if Civ 2's city was well maintained had a high pop and was well fed, the plague debuff would last for 10 turns (which would reduce population growth in the city) before going away. Using the plague strategically is well documented in history, with generals catapulting infected corpses behind enemy walls during a siege. The above is just an idea regarding how Civ could be played if these disease's were in play. As I said earlier, I have a list of diseases for each Civ that could play out differently depending on what Civs were in a game. This is just my own ramblings on what I think would be an awesome inclusion into this game, I'll also post this in the mod section to see what others think. Cheers!