2000 Edit

-Events of Half-Life: Induction occur.

May 16: Resonance Cascade Events Edit

-Events of Point of View and Azure Sheep occur.

-Events of Half-Life: Blue Shift occur.

-Events of Visitors occur.

-Events of Half-Life occur.

-Events of Sweet Half-Life occur.

-Events of Case Closed occur.

-Events of Life's End occur.

-The Black Mesa Incident (Resonance Cascade) occurs.

-Events of Half-Life: Zombie Edition occur.

-Events of Half-Life: Opposing Force occur.

-Events of Cleaners Adventure occur.

-Events of Operation Nova occur.

Post-Black Mesa Nuking Edit

-Events of Absolute Redemption occur.

2004 Edit

-Events of Random Quest occur.

-Events of 1187 Episode One occur.

7 Hour War: Combine invasion, Earth is lost. Edit

2004-2006 Edit

-Events of Human Error occur.

2009 Edit

-Events of MINERVA: Metastasis occur.

2015 Edit

-Events of Combine Destiny occur.

2018 Edit

-Events of Research and Development occur.

2019 Edit

-Events of Wivenhoe: The Fall of Ravenholm occur.

2020 Edit

-Events of Half-Life Precursor occur.

-Events of Half-Life 2 occur.

-Events of Combine Combat occur.

-Events of Riot Act occur.

-Events of Union occur.

-Events of Forward Motion occur.

-Events of Half-Life 2: Episode 1 occur.

-Events of Dangerous World occur.

-Events of Half-Life 2: Episode 2 occur.

-Events of Half-Life 2: Dawn occur.

Alternate Timelines Edit

The alternate timelines are born from the rupture of the space-time continuum due to the massive Portal Storms that had occurred from the Resonance Cascade. Therefore, they are considered as "parallel universes", not fitting in the Half-Life "key" universe.

2003 Edit

-Events of the Timeline Series occur.

Black Mesa Incident to Post-7 Hour War Edit

-Events of Calamity occur.

2003 Edit

-Events of Todesangst 1 and 2 occur.

June 2004 Edit

-Events of Poke 646 + Poke646 Vendetta occur.

2020 (G-Man's Timestop): Edit

-Events of Coastline to Atmosphere and Strider Mountain Events (SPY-maps) occur. Edit

-Events of Mission Improbable occur. Edit

-Events of City 17 Street occur. Edit

2066 Edit

-Events of USS Darkstar occur.