System Shock 2 is an action role-playing survival horror video game for Microsoft Windows, Apple OS X and GNU/Linux. The title was designed by Ken Levine and co-developed by Irrational Games and Looking Glass Studios. Originally intended to be a standalone title, its story was changed during production into a sequel to the 1994 PC game System Shock; the alterations were made when Electronic Arts—who owned the System Shock franchise rights—signed on as publisher. System Shock 2 was released on August 11, 1999, in North America.

The game takes place on board a starship in a cyberpunk depiction of 2114. The player assumes the role of a lone soldier trying to stem the outbreak of a genetic infection that has devastated the ship. Like System Shock, gameplay consists of first-person shooting and exploration. It also incorporates role-playing system elements, in which the player can develop unique skills and traits, such as hacking and psionic abilities.

System Shock 2 received positive reviews when released, but failed to meet commercial sales expectations. Many critics later determined that the game was highly influential in subsequent game design, particularly on first person shooters, and considered it far ahead of its time. It has been included in several "greatest games of all time" lists. In 2006, Computer and Video Games reported that System Shock 3 may be under development, but conclusive details have not surfaced about its project's status. In 2007, Irrational Games released a self-proclaimed spiritual successor to the System Shock series, titled BioShock, to critical acclaim and strong sales.