I'm currently working on a mod civilization. However, my UA is supposed to add a penalty to the specialists, specifically in form of -1 food per specialist to compensate for a powerful effect. Using XML to simply modify the food yield by -1 didn't work, which leads me to suspect that yields, whether it come from buildings, tiles (considering the example of the radioactive fallout modifier), or specialists, can't go below 0. I'm currently trying to do it the dummy building fashion, but I'd like to know if there is a way to implement this penalty should my dummy building method fails. SOLVED: Dummy building can produce negative yield.