Half-Life (series)
Half-Life, is a series of video games created by Valve Software. The Player plays as a character named Gordon Freeman, who is a survivor of a terrible accident at the Black Mesa Science Research Company. A group of scientists make a portal to another Dimension, and accidentally let in many alien monsters that start killing everyone.
In the first game, Half-Life, made in 1998, you play through this disaster and try to escape.
In 2004, the sequel, Half-Life 2, was released. Half-Life 2 was followed by two expansions, Half-Life 2: Episode One and Half-Life 2: Episode Two.
Half-Life 2: Episode Three, the next game, is currently in production.[1]
A related game, Portal, was released in 2007 and takes place in the same universe. Portal, Half-life 2, Half-Life 2: Episode One, Half-Life 2: Episode Two, and Team Fortress (an unrelated game) were put together into one package for sale in 2007. This package is known as The Orange Box.