In the far future, you play, in turn, three opposing sides of an interplanetary war. First, you play the humans as you are forced to fight your own kind in rebellion even while the evil Zerg are advancing on you. Then you play the Zerg has they make their pitiless conquest across the galaxy. Finally, you play a leader of the Protoss, an advanced race which is determined to defeat the Zerg, but to do so will require civil war with their own kind and an alliance with the human rebels from the human section.