Half-Life is a science fiction first-person shooter computer game developed by Valve Software and published by Sierra Entertainment in 1998, based on a very changed Quake game engine. It was first published for PCs running Microsoft Windows, and was later ported to Sony's PlayStation 2 video game console. A port for the Dreamcast was planned, but was cancelled. It is the first game in the Half-Life series.

Half-Life, often shortened to HL, has been thought to be very great by computer game critics for its gripping in-depth storyline, which has influenced the development of many other first-person shooters after it. It became very popular after it was released and still has many fans.

Plot
The story of the game takes place in a science research facility in New Mexico named Black Mesa. In the game, you play as Gordon Freeman, a scientist who works at Black Mesa. A test that Gordon helps with goes wrong, and causes a "resonance cascade", or a hole in the fabric of reality. This causes portals to appear all over Black Mesa. Aliens from a different dimension come through the portals and kill many of the scientists and workers. The dimension that the aliens come from is called Xen. After that, the United States Military is ordered to kill all the scientists and aliens in Black Mesa because they didn't want people to know about the accident. Gordon must fight aliens and marines on his way through Black Mesa, then teleport to Xen so he can kill the alien leader.

Expansions

Half-Life: Opposing Force 
Half-Life: Opposing Force is the first expansion for Half-Life, which was made by Gearbox Software instead of Valve. It was released on November 1, 1999. Half-Life: Opposing Force happens during the same time as Half-Life and in the same setting. In the expansion, you play as "Adrian Shephard", a United States marine. He was sent to Black Mesa, and must escape after the helicopter he was riding was shot down.

Half-Life: Blue Shift 
Half-Life: Blue Shift is the second Expansion for Half-Life, which was also made by Gearbox Software, and was released on June 12, 2001. Half-Life: Blue Shift happens during the same time as Half-Life and in the same setting, just like Opposing Force. In this expansion, you play as "Barney Calhoun", a security guard who works at Black Mesa during the resonance cascade.

Half-Life: Decay 
Half-Life: Decay is the final expansion for Half-Life. Only the PlayStation 2 version of Half-Life has it. A few years after it was released, though, some fans of Decay made a version of it for the computer, and released it as a mod. The expansion is a cooperative multiplayer campaign, where two players have to work together to win.

Characters

G-Man 
The G-Man is a mysterious character that constantly appears in the Valve Software games Half-Life, Half-Life 2, Half-Life 2: Episode One, Half-Life 2: Episode Two and Half-Life: Alyx.

As of yet it is not yet certain who the suit-wearing man is, although it is commonly agreed that he has a pivotal role to play in the upcoming Half-Life 2: Episode 3. Avid followers of the series will know that he appears in almost every game level (see G-Man Locations), and lots of fan sites have been set up in his honor.

Gordon Freeman 
"Gordon Freeman" is a scientist that worked at the Black Mesa Research Facility before the main events of the game and is the main character in Half-Life.

Xen extraterrestrials 
Aliens from the dimension known as Xen.

Sequels 
Half-Life has 2 sequels, Half-Life 2 (including its episodes), and Half-Life: Alyx, a VR interquel that follows the character Alyx Vance.

References

Shooter video games
1998 video games
Half-Life series