S. T.a.l.k.e.r. is a series of first person shooting survival horror video games developed by GSC game world, a Ukrainian video game developer, for Microsoft Windows. These games are very loosely based on the novels "roadside picnic" by strugatsky brothers and the film of Andrei Tarkovsky in 1979《 Stacker, these games are set in the area near the scene of Chernobyl accident, commonly known as "area". In another case, there will be a second explosion of Chernobyl nuclear power plant in a period of time after the first Chernobyl nuclear power plant, resulting in strange changes in the surrounding area.

S. The t.a.l.k.e.r. game is played in the area, an alternative historical version of the Chernobyl exclusion zone. In the game world, an experimental laboratory has been set up in the forbidden area, which enables scientists to test the psychological ability after disasters. Their experiments led to a second disaster, with physical and meteorological phenomena appearing throughout the region, as well as mutations in fauna and some humans. The region is littered with "anomalies": dangerous entities that seem to violate physical principles and have various effects on any object entering them.

Anomalies often produce objects called "artifacts" that have special physical properties, such as anti gravity or absorption of radiation. People enter the "development zone" in the hope of finding such items to obtain personal financial benefits. These people are known as "stalkers.". Although a large number of troublemakers work alone, various factions still gather in the "region", and each faction has its own ideas and goals. For example, the watchmen believe that the "safe zone" is the greatest threat to mankind on earth and intend to destroy it in any possible way; in contrast, the Liberals believe that all people should have access to the "zone".

The Ukrainian armed forces maintain a cordon around the security zone in an attempt to prevent the entry of any unauthorized personnel. In addition, the Ukrainian SPETSNAZ forces carry out special operations in the area, such as surgical strikes on potential divers or ensuring the safety of specific targets. Other hostile entities in the area include humans and other creatures that mutate after two disasters, many of which have offensive powers.

The protagonists of each game have their own goals, separate from the goals of each faction, but they have the opportunity to assist others in their plans. Usually, the ultimate goal of each game is to reach the center of the area, which is complicated by various threats and dangers.