Warcraft II: Tides of Darkness is a fantasy-themed real-time strategy (RTS) game published by Blizzard Entertainment and first released for DOS in 1995 and for Mac OS in 1996. The main game, Warcraft II: Tides of Darkness, earned enthusiastic reviews, won most of the major PC gaming awards in 1996, and sold over 2 million copies. Players must collect resources, and produce buildings and units in order to defeat an opponent in combat on the ground, in the air and in some maps at sea. The more advanced combat units are produced at the same buildings as the basic units but also need the assistance of other buildings, or must be produced at buildings that have prerequisite buildings. The majority of the main screen shows the part of the territory on which the player is currently operating, and the minimap can select another location to appear in the larger display. The fog of war completely hides all territory which the player has not explored. Terrain is always visible once revealed, but enemy units remain visible only so long as they stay within a friendly unit's visual radius.