Canon

Canon is what refers to all material deemed to be set in the final Half-Life storyline.

Certified canon material

 * Half-Life
 * Half-Life 2
 * Half-Life 2: Episode One
 * Half-Life 2: Episode Two
 * Portal
 * Half-Life 2: Episode Three

Ambiguous canon material

 * Half-Life: Opposing Force
 * Half-Life: Blue Shift
 * Half-Life: Decay

Cut material

 * Half-Life: Uplink
 * ''Half-Life 2 Beta
 * Half-Life 2: Lost Coast