The original game. On steam, Half-Life: Uplink was added into the base game ever since the anniversary update

A demo level released for free, not a cut chapter like many people seem to believe. Was made available on the Steam version of the game via the Anniversary Update.

The first of three expansion packs for the original Half-Life, and often considered to be the best.

The second expansion pack for the original Half-Life, originally meant to be a Dreamcast port exclusive. However, due to the cancellation of said port, the expansion was brought to PC and is available via Steam.

The third and final expansion pack for the original game, and the only one to NOT be available (officially) on Steam. It is exclusive to the PS2 version of the game and plays as a co-op game, similarly to Portal 2 co-op.

The sequel to the original. Also includes the episodes and lost coast thanks to the anniversary update on Steam.

A short chapter that was cut from the game and released as a standalone experience. Was merged along with the episodes into the base game on Steam since the Anniversary Update.

The first of two episodic expansions. Nowadays available directly through the base game on Steam.

The second of two episodic expansions. Nowadays available directly through the base game on Steam.

VR-Exclusive prequel of the second game and the most recent entry in the series.