LeeS, I'm experiencing a bug. Dummy buildings are appearing when the prerequisites have not been met. I have made no alterations to your code. Followed your instructions exactly. The only other mod that I have activated is MOAR units. Here are three examples of the problem: 1. I created multiple dummy buildings that require resources and a base game building. The Market requires one of these dummy buildings to be be built. I meet the requirements for one of the dummy buildings like the Bakery which requires Wheat or Rice and the Granary. The Market unlocks and I begin building the building. Then about two turns later all of the other Market prereq dummy buildings appear in the city even though their prereqs don't exist. This was happening consistently. I had to remove the Market prereqs. 2. The Field Cannon requires the dummy building called the Siege Factory or the Palace. The Siege Factory requires a Blacksmith(dummy) or Bronzesmith(dummy) and Niter. The Blacksmith builds if Iron is improved and the Bronzesmith builds Copper is improved. In this situation the only prereq that existed was the Palace and improved Niter. I had no Copper or Iron. I begin constructing the Field Cannon when the Siege Factory suddenly appears with no explanation. 3. Sometimes the dummy buildings randomly appear in cities when the prereqs don't exist. Then one or two turns later they disappear. This happens frequently. One example: I settled a new city and a dummy building (Goldsmith) appeared immediately. The prereq building (Theater) wasn't constructed and no resources (Diamonds, Copper, Silver) were improved. The required resources didn't even exist around the city. I checked the city two turns later and the dummy building disappeared from the city list.