Maps

§ There are three different kinds of maps in Civilization IV: the main map, the mini map, and game maps. The main map and the mini map are sections of Civ IV's interface; see the manual for details on them. This entry deals specifically with game maps.
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Game Maps

§ Game maps are maps of portions of the world. You can acquire game maps from friendly villagers, or from other civilizations.
§ Maps from Villagers
§ When one of your units enters a village, the villagers may respond by giving you a map of local territory. When they do so, your main map is updated to display the newly-revealed territory. This territory is "explored" (see Exploration for more details).
§ Trading Maps
§ The Paper technology allows you to trade maps with other civilizations. When a civilization trades you a map, all of the territory that civilization has "Explored" is updated on your main map. When you trade another civilization your map, that civilization learns about all of the territory that you have explored.