Short about S.T.A.L.K.E.R. universe.

S.T.A.L.K.E.R. universe is mostly a game and book universe , influenced by the book , known as Roadside Picnic and withh all the events tied with Chernobyl Exclusion Zone - a place of ecological disaster since the explosion of the 4th reactor of Chernobyl Nuclear Powerplant in 1986, though after that event the group of USSR scientists started to work there , creating a secret laboratories , known as X-Labs(like X-16,X-18,X-10 , etc)which were creating different projects , like supersoldiers and some weapons , plus devices that would be able to create a psy-distorbtion pulses-energetic pulses , that were able to affect the mind and reprogramm those or destroy completely .
But that's not the worst thing , the worst thing was their test with trying to contact the noosphere-earth's informational field and rewrite it , trying to delete all negative factors , like cruelty , greed and so on but it all went out of the control and a huge ammount of Noosphere energy hitted the local biosphere ,turning everything in a 60 -killometers of Chernobyl Exclusion Zone-place filled with mutants , radiation , psy-disturbtion areas , anomalies and so on .
But after 2006 it turned out that anomalies are also able to turn some stuff , like dirt , trash or flesh , that got into it into the strange items with it's all positive and negative effects , known from now on as artifacts, and those things turned to be a valuable objects for scientists , due to some of them having quite an interesting effects , like increasing regeneration , creating gravity fields around it user or protecting from radiation ,of course , those objects turned to be valuable for a black market and could be solled ouside of the Zone for millions or even billions of dollars.
And of course that brought a lot of people who would like to test their luck in there , hide from law or anything else ,known from now on as stalkers-individuals who sneak hrugh the Zone and try to survive in that hell , while trying to get a lot of money or achieve their own goals , not to mention the different stalker fractions like Duty- formal Ukranian troopers who were left by their allies , that united with some stalkers nd follow their idea of destroying the Zone , Freedom - group of anarchists that want to make it their own country and give a free passage to everyone . Merc Syndicate- a mysterious group of bounty hunters that getting a huge ammount of US and Europian weapons , that following the orders of more mysterious clients.Scientists -enogh said.Ukraine Militaries-that trying to block the entrance and take control over the place , though having corrupted members in their ranks,.Loners-lone stalkers that have no ideology and follow their own philosophi , rarely uniting and or walking in groups , Bandits-thugs and USSR criminals that entered the Zone in order to hide from law and known for robbing others and so on.