I'm not sure about this one. That maybe too precious of a skill for Expert Prospectors, makeing their aquisition extremely important, leaving your empire gimp without them. This is somewhat how it works now. When a Map is generated and after a Bonus Iron is placed, that Bonus Iron plot acts like a Mining Epicenter. Ore is then added around the Bonus for several plots. This Ore is then already on the map and your Prospectors can find it. The amount of Ore Grows larger the closer you get to the Epicenter so when Prospecting you may can tell what direction the Bonus is. Bonuses are not hidden at the moment so you can find it once the plot is revealed. There is also a random chance to find Ore in any viable plot, but the Epicenters guarantee Ore. Yeah, good idea. The Type of Terrain can have a bonus to the Amount of Ore Revealed. I made some additions to the Prospecting code. When you deplete an Ore source you will get a message and a plot Icon, also the unit working the plot will be auto reassigned to another plot so you want keep producing nothing. I plan to add Silver and Stone to this system next. I am still waiting to here from Night about the mentioned bug before I make another upload.