

Gordon Freeman, a recently employed theoretical physicist for Black Mesa, is involved in an experiment analyzing a strange, unknown crystal. The Half-Life series begins in 200-, at the Black Mesa Research Facility, deep below the New Mexico desert. Gordon Freeman, the main protagonist of the Half-Life series. In the spin-off series, including Portal and its sequel, Portal 2, the main protagonist, Chell, a Test Subject, is detained in the Aperture Science computer-aided Enrichment Center, run by the A.I. In the canon expansions and spin-offs, the featured playable characters are not Gordon Freeman, but rather a HECU Corporal, a security guard, and a pair of scientists, all of them as eager as Gordon to make their way out.

The protagonist of the Half-Life series is Gordon Freeman, a former Black Mesa employee whose attempt to escape from Black Mesa ends up in his employment by the G-Man.


Starting on the GoldSrc engine, a modified Quake engine, the series now runs on the Source engine. Since its first installment, the series has been introduced to many consoles such as the PlayStation 2, PlayStation 3, and Xbox 360, as well as Mac. In 2005, Electronic Arts took over distribution of the Half-Life series. Most of them were developed by Valve however, Half-Life's three expansions, Blue Shift, Opposing Force and Decay were developed by Gearbox Software. Half-Life has spawned since then many modifications, expansions, and sequels, most of which set in the same universe. It is told through five related story arcs, each stemming from a game: Half-Life, Half-Life 2, Half-Life: Alyx, Portal, and Portal 2. The Half-Life and Portal universe, also known as the Half-Life universe or the Portal universe, is a science fiction universe created by Valve Corporation in 1998, with the release of the video game Half-Life on the PC platform.
