Fog of Intelligence The map is overlaid with a veil of darkness obscuring areas of the world your people have never explored. As units move over the surface of the world they reveal the unexplored areas, brightening the areas they can currently "see." Areas that have been explored, but are not currently "seen" by your people have a soft gray veil over them. So at any time, each and every square of the map is either * unexplored in darkness * explored in grayness * seen well lit World Maps As civilizations explore the world and found new cities, they gather information and create a map of the world that is unique. For each civilization, it is comprised of the area its people currently see and the explored areas (as they were when last seen). This is called the civilization's world map and can be very valuable in negotiations with other, less knowledgeable, civilizations. You will be able to trade world maps after your civilization discovers Navigation. Territory Maps Each civilization also keeps a territory map showing areas under its cultural influence only. These are less valuable in negotiations, but still of some worth.