In the distant future, a small group of human exiles have been doomed to fight for survival on the edge of the galaxy. Through military strength, espionage, and deceit, a unified Terran government has maintained an uneasy peace. But a previously unknown species, the Zerg, has started overrunning their colonies. Furthermore, a second alien species, the enigmatic Protoss, became intent on stopping the Zerg. The Protoss solution, however, is to extinguish all life on Zerg-infested planets, including many surviving resident Terrans. At the same time, rebel factions within the Terran government are gaining popular support during the Zerg crisis. The time for war has come! Gameplay in StarCraft has clear similarities to Blizzard's earlier WarCraft II. Building units requires credits and a power source, and once completed you can direct them into combat against foes. You only know the layout of terrain you have visited, and only the exact whereabouts of enemy units which are range for one of your units, due to the Fog of War. Each of the three races has a distinct range of units and general strengths: Zerg units are quick to build, Terran units cost the least, and Protoss units are the most powerful individually. In a change from many strategy games, the base style for each race also varies significantly, resulting in a very different playing experience with each.