The primary difference is the Chernobyl reactor, which was used to study psychotropic weapons and technology. STALKER takes place in an alternate reality that is, for most intents and purposes, identical to real life. It is one of the purest 'reality + weird things' settings available. It has an open, internally-consistent world. Its characters are dressed and equipped reasonably for the settings.
It uses realism to make fantastic things seem more notable. It has a central defining element to its setting. As a game, STALKER works with a lot of the concepts that I've talked about in the past. Most gamers know it from video games: 'Shadow of Chernobyl', 'Clear Sky', and 'Call of Pripyat'.
is a setting founded on a short story ('Roadside Picnic') and a film ('Stalker') detailing an alternate reality centered around the Chernobyl disaster.
