New units are acquired during each mission, which may then be used in any future missions (except the Prophecy missions, in which the player does not use Terran units). The first three missions must be completed in order, after which a series of events occurs that enables the player to begin directing the order in which missions are played. Specifically, the player is assumed to have the role of Raynor from a third-person perspective. The Wings of Liberty Campaign follows the exploits of the Terran outlaws Jim Raynor and Tychus Findlay.
