Half-Life: Blue Shift

Half-Life: Blue Shift is an expansion pack for the first-person shooter video game Half-Life (1998). It was developed by Gearbox Software and published by Sierra On-Line. Blue Shift was the second expansion for Half-Life, originally intended as part of a Dreamcast port of Half-Life. Although the Dreamcast port was cancelled, the Windows version was released as a standalone product on June 12, 2001.

As with Gearbox's previous expansion pack, Opposing Force (1999), Blue Shift returns to the setting and events of Half-Life, but portrays the story through the eyes of another character. Players control security guard Barney Calhoun, employed by the Black Mesa Research Facility, who must fight his way to safety during an alien invasion. Blue Shift also includes a graphics pack that upgrades the Half-Life models and textures.