Depending on whether you're referring to the atmospheric video game series or the serious real-world issue of stalking, here is useful information for both.
The original trilogy consists of Shadow of Chernobyl (2007), Clear Sky (2008), and Call of Pripyat (2009). The newest entry is S.T.A.L.K.E.R. 2: Heart of Chornobyl (2024).
: The classic entry that started the series can be found at Green Man Gaming .
: Available at Green Man Gaming and G2A.com , this collection brings together the first three games for modern platforms.
For beginners, you can find a comprehensive lore breakdown or a quick start guide to survive the early game's high difficulty. Real-World Safety & Resources