I would like to know if it's possible to create a mod that adds to a policy the effect of giving a yield to a building after a certain tech is discovered. Specifically, what I want to do is make it so that the policy Honor opener provides a +1 Science bonus on Barracks, Armory and Military Academy after Military Science has been researched. My own progress: I found in the Civ5Buildings.xml file the following tag (modified from the Mughal Fort tech-dependant Gold yield): Code: <Building_TechEnhancedYieldChanges> <Row> <BuildingType>BUILDING_BARRACKS</BuildingType> <YieldType>YIELD_SCIENCE</YieldType> <Yield>1</Yield> </Row> </Building_TechEnhancedYieldChanges> Which obviously specifies a science-dependant yield, and combined with this tag: Code: <Buildings> <EnhancedYieldTech>TECH_MILITARY_SCIENCE</EnhancedYieldTech> </Buildings> can be used to create the effect I want. I also know that from the policies files, I can use the following code (modified from Organized Religion's Faith yield): Code: <Policy_BuildingClassYieldChanges> <Row> <PolicyType>POLICY_HONOR</PolicyType> <BuildingClassType>BUILDINGCLASS_BARRACKS</BuildingClassType> <YieldType>YIELD_SCIENCE</YieldType> <YieldChange>1</YieldChange> </Row> </Policy_BuildingClassYieldChanges> to add the yield to the building once the Policy is adopted. What I need help with: Is it possible to link these two pieces of code, so that the bonus BOTH becomes tied with the policy AND with the tech? And if so, how do I do it?