In S.T.A.L.K.E.R. Clear Sky, the player assumes the role of Scar, a mercenary s.t.a.l.k.e.r. In a unique mixture of first-person shooter and complex role- playing game, Scar fights for survival within the Zone and its hostile sectors. The new Zone territories are explored by s.t.a.l.k.e.r.s scattered in groups - and these individual factions soon engage in relentless battle. As a mercenary, Scar quickly finds himself in the middle of a war of factions over territory, artifacts, and power. It is up to the player to find out on whose side Scar has the greatest chance of prevailing.
Just like its predecessor, Clear Sky perfectly captures the sinister atmosphere within the death Zone. DirectX 10 support enables spectacular graphics, including dynamic transitions between day and night with absolutely realistic light effects, as well as very detailed landscapes and lifelike animations. At the same time, the developers saw to it that S.T.A.L.K.E.R. Clear Sky also works with DirectX 8 and DirectX 9.
Special attention was given to realistic, independent thinking and actions of the NPCs. The artificial intelligence from the predecessor game was strongly improved, so that foes and allies now make their own situation-based decisions that impact the further course of the game. For instance, the outcome of battles is not predetermined. Only in the last few levels is the player guided towards a given end of the story, which leads to the events described in Shadow of Chernobyl.