The second installment of the S.T.A.L.K.E.R. franchise is set one year before the events of Shadow of Chernobyl and serves as its prequel. You will explore the forbidden area around Chernobyl, Ukraine, after a new disaster that turned into The Zone, a post-apocalyptic wasteland full of mutants. The setting was inspired by a Russian sci-fi book Roadside Picnic and its adaptation Stalker. Scar, the main character of Clear Sky, is a stalker, which in this world is a term for guides and explorers in The Zone. He was hit by an energy beam that gave him a superhuman ability to survive The Zone’s phenomena. Scar joins the Clear Sky, a secret science organization that studies The Zone’s anomalies. Strelok, an important character from the previous game, appears as the main antagonist.
Like its predecessor, Clear Sky is a combination of first-person shooter gameplay with RPG mechanics like skills, leveling up, dialogue, and inventory. The player is free to explore the open world and accept quests unrelated to the central plot from various NPCs and factions. Compared to Shadow of Chernobyl, the prequel has improved graphics, additional options for customization and equipment repair and a complete day/night cycle.