Half-Life 2: Episode One

Half-Life 2: Episode One

Developer(s)

Valve Corporation

Publisher(s)

Electronic Arts (retail)
Valve Corporation (Steam)

Series

Half-Life series

Release date(s)

June 1, 2006

Genre(s)

First-person shooter

Mode(s)

Single-player

Platform(s)

Windows, macOS, Linux, Xbox 360, PlayStation 3, Android (Nvidia Shield)

Engine

Source (Source 2013 SP)

Steam AppID

380

Written in

C++

Mod support

Yes (custom folder, Steam Workshop)

SDK

Source SDK

System requirements

• Win Vista, 7 or later
• 1.7 GHz and/or Dual-core
• 1 GB RAM
• 6.5 GB disk space
• DirectX 9.0 compatible (with DX 8.1 level card)

New Engine only. For details, see below

Distribution

Retail, Steam

Links

Steam Store page (unlisted)
Steam Workshop
ModDB page

Previous game

Half-Life 2: Lost Coast
Half-Life 2 (chronologically)

Next game

Half-Life 2: Episode Two

Half-Life 2: Episode One is the first in a series of games that reveal the aftermath of Half-Life 2 and launch a journey beyond City 17. It focuses on developing Alyx as a character.

Consciousness returns. Gordon and Alyx discover they've somehow escaped both the reactor explosion and the G-Man's malevolent grasp. Before they can ponder their miraculous survival, the crippled Citadel lurches back to life just long enough to initiate a self-destruct sequence. With Alyx at his side, Gordon must flee a city in chaos before the Citadel's final detonation turns City 17 into a toxic, mutant-infested crater.

Aside from the story, the game initially runs on Source 2006, which introduced new features such as HDR, Phong shading, and much more. The game was later upgraded to Source 2009, then again with Source 2013 Singleplayer.

With the release of Half-Life 2 20th Anniversary Update in November 16, 2024, both Episode One and Episode Two are now accessible through Half-Life 2 main menu. As a result, both episodes are unlisted from the Steam Store.

Content

• Half-Life 2: Episode One (episodic)
• Half-Life 2 maps (hl2)
• Source shared (hl2)
• Source 2013 Singleplayer engine branch

Chapters

Half-Life 2: Episode One Chapters
Undue Alarm ep1_citadel_00	Direct Intervention ep1_citadel_03	Lowlife ep1_c17_00	Urban Flight ep1_c17_01
Exit 17 ep1_c17_05

Gallery

• 

System Requirements

Windows (Old Engine/original requirement):

• OS: Windows 98 / ME, 2000, XP or later
• CPU: 1.2 GHz (Pentium 4 or Athlon 2800+ processor)
• RAM: 256 MB
• Disk space: 4.5 GB
• GPU: Nvidia GeForce FX 5700, ATI Radeon 9500
• Direct3D 9.0 compatible video card (with atleast DirectX 7.0 or higher feature level) and 128MB VRAM
  Some features such as HDR and color correction requires DirectX 9.0 or higher graphics card (Nvidia GeForce 6 series or ATI Radeon 9000/X300-X600/X800) series

Windows (New Engine):

• OS: Windows Vista, 7 or later
• CPU: 1.7 GHz and/or Dual-core
• RAM: 1 GB
• Disk space: 6.5 GB (15GB+ recommended)
• GPU: NVIDIA GeForce 6 series, ATI Radeon X1600, Intel HD Graphics 3000 (with 128MB VRAM)
• Direct3D 9.0 compatible video card (with atleast DirectX 8.0 or higher feature level)
  Some features such as HDR and color correction requires DirectX 9.0 or higher graphics card.

Note:A powerful DX9 or later card is highly recommended because the new engine (Source 2009, Source 2013) are more demanding to run, compared to old engine/previous versions.

Note:The latest version is no longer compatible with XP since the 2022 Steam Deck update.
User using these OS can downgrade to previous version of the game by using the previous beta branch (dated from Sep 2019). But please note that this older branch does not include all the bug fixes that were introduced with Steam Deck update.

Note:Due to Steam dropped support on Windows XP/Vista, users need run the game without Steam by running the hl2.exe executable with -game episodic.

OS X:

• OS: OS X 10.5.8, 10.6.3 (up to 10.14.6)
• CPU: 2.0 GHz and/or Dual-core
• RAM: 1 GB
• Storage: 6.5 GB (15GB+ recommended)
• GPU: NVIDIA GeForce 8xxx series, ATI Radeon X1600, Intel HD Graphics 3000
  OpenGL 2.1 compatible
• Audio: OpenAL compatible

Note:Mac version are no longer supported after macOS Catalina (10.15), due to this game only have 32-bit binaries.
User can manually build Intel 64-bit/Apple Silicon version of HL2 by following this guide.

Linux:

• OS: Ubuntu 12.04, SteamOS 1.0 or later
  Other Linux distros supported.
• CPU: 2.0 GHz and/or Dual-core
• RAM: 1 GB
• Storage: 6.5 GB (15GB+ recommended)
• GPU: NVIDIA GeForce 8xxx series, ATI Radeon X1600, Intel HD Graphics 3000
  OpenGL 2.1 compatible
• Audio: OpenAL compatible

Note:The system requirements for Half-Life 2: Episode One on Linux are unofficial, based off Windows/Mac info, as well as other Source games that support Linux, such as Portal 2.

Limitations/Bugs

• For the list of Half-Life 2: Episode One bugs, see this GitHub page.

External links

• Half-Life 2: Episode One on Combine OverWiki
•  Half-Life 2: Episode One on Wikipedia