I want to make things happen after a certain duration of turns. For example, a building in your city that might get stronger or weaker over time. Or tiles on the map that might gain or lose resources over time. I'd also like to be able to do some form of temporary boost effects like the pillars.



They are share a common trait though which is the ability to have stats change over time, and I can't seem to find any examples of how to do this in the existing XML files. Is this all hard coded and therefore impossible to do as a mod?



I almost feel like it can be done but i'm just missing some of the connective tissue to make it work. For example I can see that there is a property for current turn on the ClassEmpire. Maybe I can save that current value at the time of a building construction, and then... what.. There I go losing the thread.



Let's take an example... um..



Over Farming

Once constructed in your city, will increase the food yield on all tiles with food for a period of time, but in the long term will reduce the overall food output of the tiles.

+3 Food on Tiles with Food for 50 turns

-1 Food on Tiles with Food for all turns after



How would I go about making this? Is it possible?