S.T.A.L.K.E.R.: Shadow of Chernobyl, is a first-person shooter computer game by Ukrainian developer GSC Game World.
It features an alternate reality theme, where a second nuclear disaster occurs at the Chernobyl Nuclear Power Plant in the near future and causes strange changes in the area around it. The game has a non-linear storyline and features gameplay elements such as trading and two-way communication with NPCs.