Can someone help me on how to adjust the Extra Attack Percentage from a Feature. Say I want a unit to get an attack bonus when he is on a Forest-tile with a river. I know how to read an Attack Percentage when it is set in the XML-file via <UnitPromotions> - <Attack> local pUnit = UI.GetHeadSelectedUnit(); local pPlot = pUnit:GetPlot(); local pFeature = pPlot:GetFeatureType(); local pBonus = pUnit:GetExtraFeatureAttackPercent(pFeature); print (pBonus) But say I want to adjust this percentage from 25 to 50 when the plot has a river. How would I do that? I guess I would need the FeatureAttackModifier. In the wiki it is defiened as: int unit:featureAttackModifier(FeatureTypes eFeature); So I guess I should check if there is a river on the plot: pPlot:IsRiver And then change the bonus with something like: pUnit:FeatureAttackModifier(pFeature, 50); But when I try this and I read it after updating, it is not changed. I guess I am doing something wrong. Hope someone can help me out.