Half-Life (series)

Half-Life series
The series' logo, an orange lambda, is a prominent symbol throughout the series
Developers	Valve Corporation (1998–present) Gearbox Software (1999–2001)
Publishers	Sierra Entertainment (1998–2003) Valve Corporation (2004–present)
Platforms	Windows OS X Linux Xbox Xbox 360 PlayStation 2 PlayStation 3 Shield Portable
Platform of origin	Windows
First release	Half-Life November 19, 1998
Latest release	Half-Life 2: Episode Two October 10, 2007

Half-Life (stylized HλLF-LIFE) is a series of first-person shooter video games that share a single science fiction alternate history. The games in the series all utilize either the GoldSrc or Source engines and are linear, narrative, single-player titles.

Valve Corporation is the developer, and partly the publisher and distributor, for their signature games of the series. The major titles in the series feature the player as the protagonist, Gordon Freeman, a theoretical physicist initially employed by the Black Mesa Research Facility. Two of these games, Half-Life and Half-Life 2 are full length titles, while two more, Half-Life 2: Episode One and Half-Life 2: Episode Two, are shorter, episodic titles. A final episode, Half-Life 2: Episode Three, was originally scheduled to appear around Christmas 2007, but now has no public release date.

A puzzle-based first-person series, set in the same fictional universe as the Half-Life games, was created with Portal in 2007, followed by a sequel, Portal 2, in 2011.

Half-Life, the first game in the series, takes place at the fictional Black Mesa Research Facility in New Mexico circa the turn of the 21st century. Gordon Freeman, a theoretical physicist, is involved in an experiment that accidentally creates a dimensional rift to a trans-dimensional world called Xen, causing extraterrestrial life to swarm the facility and kill the survivors. As Freeman and the survivors try to flee, a Marine Recon unit is brought in to contain the situation, including killing those that try to escape. Freeman ultimately makes his way to Xen and eliminates the alien "leader", the Nihilanth, but then is confronted by the G-Man, who places Freeman into stasis.Half-Life: Opposing Force follows Recon soldier Adrian Shephard as he helps to quell another alien invasion within the Black Mesa facility. Within Half-Life: Blue Shift, Black Mesa security worker Barney Calhoun works to escape the facility from both alien forces and the Recon soldiers with Dr. Rosenberg and two other scientists.