System Shock is a landmark immersive sim set aboard the derelict space station Citadel, where a rogue artificial intelligence named SHODAN has seized control. Players explore the station's decks, scavenging resources while facing mutated crew and security systems.

Combining first-person combat, hacking, and open-ended exploration, it lets players tackle threats through multiple approaches, and its tense atmosphere and clever design have made it hugely influential on the genre.