Half-Life 2

Half-Life 2 (abbreviated as HL2) defines a new benchmark in gaming with startling realism and responsiveness. Powered by then-new Source technology, Half-Life 2 features the most sophisticated in-game characters ever witnessed, advanced AI, stunning graphics and physical gameplay. This was the first game requiring installation of when it came out back in 2004.
Half-Life 2 is the sequel to the 1998 Half-Life. A sequel to Half-Life 2 was released in 2006, titled Half-Life 2: Episode One, followed by in 2007, being the last Half-Life 2 episode. A virtual reality prequel was released in 2020, titled Half-Life: Alyx.
Half-Life 2 was later ported for the Xbox console in 2005, as well as for the Xbox 360 and PlayStation 3 in 2007, bundled under The Orange Box.
A major update (Half-Life 2 20th Anniversary Update), has been released on November 16, 2024 to celebrate the 20th anniversary of the game. It adds Steam Workshop support, developer commentary, fixing various bugs, and both episodes (, ), aswell as now accessible directly on Half-Life 2 menu. There are also many other changes to the graphics, such as "Very High" shaders that enable Bicubic lightmap filtering, and option to use classic fire/blood particle effect.
== Features ==
This section only features changes exclusive to (and partially or mods base directly on instead of SDK 2013), such as the recent 20th anniversary update. For features introduced in Source 2013 SP branch, see this page. For Source engine features, see Source engine page.
; VGUI High DPI support 
: VGUI are now properly scalable on higher resolutions such as 4K (3840x2160).
; lightmap filtering 
: Introduced in 2024, bicubic filtering is used on lightmaps when is enabled, smoothing out aliasing caused by the lower resolution of lightmaps. It can be also enabled by setting the Shader detail to "Very High".
; Radial fog 
: Unlike planar-based fog, radial fog does not strengthen or weaken the apparent amount of fog in a particular spot when you rotate the camera. 
: You can either use radial fog or planar-based fog by changing "Use Radial Fog " KeyValues.
; Continue music playback after loading levels 
: Introduced in HL2's November 26, 2024 Update, music will continue to play after the next level is loaded, instead of stopping completely like in previous versions. Can be toggled using console command.
== Content ==
* Half-Life 2 content (hl2)
* Half-Life 2: Episode One content (episodic)
* Half-Life 2: Episode Two content (ep2)
* Half-Life 2: Lost Coast content (lostcoast)
* Half-Life 2 Complete (hl2_complete)
** On Steam, the game will be launched with , allowing users to switch to HL2, EP1, EP2 and Lost Coast through the menu (similar to on & ). Running directly will instead launch , with old UI font and without option for switching games through menu.
* Source shared (hl2)
* Source 2013 Singleplayer engine branch
== Other versions of Half-Life 2 ==
=== Demo ===
Half-Life 2 has a demo version, available for free. The demo consists of excerpts of the Point Insertion and Ravenholm chapters ( and ) and "We Don't Go To Ravenholm..." (, and ).
=== Half-Life 2: Update ===
Half-Life 2: Update is the mod developed by Fillip Victor, which improves Half-Life 2 by fixing bugs and featuring graphical improvements. However, this mod is no longer updated since 2015 and does not feature any updates, new bug fixes and features from Steam Deck update, Anniversary Update introduced in original Half-Life 2.
=== Half-Life 2 RTX ===
A ray-traced version of Half-Life 2 is currently under development by Orbifold Studios, and promoted by , using Nvidia's RTX Remix tool.
This version aims to remaster the entire game with new ray-traced lighting, real-time reflections, PBR textures, and a lot more without changing the core gameplay, similar to Portal RTX.
== Chapters ==
Half-Life 2 has 13 chapters (excluding Credits). In the demo version of the game, only two Point Insertion maps ( and ) and "We Don't Go To Ravenholm..." (, and ) is playable.
== NPCs ==
== Credits ==
== Limitations/Bugs ==
*For more Half-Life 2 bugs, see this GitHub page.
This section only list various bugs that are commonly encountered.
=== ===
None.
=== ===
; Missing lighting on LDR / LDR with Bloom
:Previous version of Half-Life 2 from 2010 to 2023 lacks LDR lighting on multiple game levels (starting from Black Mesa East () until the end of Nova Prospekt). This means that if HDR is disabled (by selecting "None" or "Bloom only" in HDR settings), mat_fullbright will be set to 1, disabling lighting and making everything bright and flat (relevant GitHub issue). Because of this, HDR is required to play the game until this is fixed.This issue is not affected in the previous version of the game (which uses an older version of Source () and all of the maps lighting are compiled in LDR only), and is fixed in Half-Life 2: Update, aswell as 20th Anniversary update.
; Dropship NPC gun broken
:There was a bug with the Dropship's gun that was unable to turn, this makes the Sandtraps chapter much easier. This bug was introduced with engine branch and later, affecting both the console release of the game on X360/PS3 (remains unfixed) and later in 2010 with the engine update on Mac & PC release.Fixed in the current Steam version since 2022's the Steam Deck update of Half-Life 2. However, there are many third-party Source mods (including , , etc...) which may or may not include this fix, plus the code also does not include this fix by default; this page details how to fix it in your mod.
=== Other limitations ===
As of May 26, 2010 (Mac), and later June 2010 on Windows, the branch of Source under which Half-Life 2 originally ran on Source 2006 no longer exists on Steam, and subsequently replaced by the updated Source 2009 (which later was upgraded again to Source 2013). Very old mods which base themselves directly on the game (as opposed to Source SDK Base) are unlikely to work any more. This also meant that support for running Half-Life 2 on Windows 9x/ME/2000 have been also dropped.
The console port of the game for original Xbox, and (on ), no longer received any updates or bug fixes.
== Technical notes ==
* In the 2006 version of the game, being underwater at d1_canals_01, or in some area on that same map can cause performance drops. Fixed since 2010 with the engine update.
* Although Source mods are often described as being "for Half-Life 2", they actually use the Source SDK Base. SDK Base is available to anyone who owns any Valve Source game and provides all of Half-Life 2's content (except maps and vcd scenes) on a static branch of the engine.
* The Half-Life 2 Collectors Edition, which ships with the 2004 version of the game, does not require Steam to run or update (similar to the latest version), which means that it will run on older systems with Windows 2000 and earlier. Since around 2010 or 2013, Half-Life 2 no longer requires Steam to run after installing it through Steam, but features such as Achievements will be unavailable.
* The 64-bit Windows version of Half-Life 2, which existed around 2005-2006, is no longer available.
== System Requirements ==
Windows (Old Engine):
*OS: Windows 98 / ME, 2000, XP or later
*CPU: 1.2 GHz 
*RAM: 256 MB 
*Disk space: 4.5 GB
*Nvidia GeForce FX 5700, ATI Radeon 9500 (with 128MB VRAM)
*Direct3D 9.0 compatible video card (with atleast DirectX 7.0 or higher feature level) and 128MB VRAM
*Other: Steam required (except Collector's Edition copies)
Windows (New Engine):
*OS: Vista, 7 or later
*CPU:1.7 GHz and/or Dual-core 
*RAM:1GB RAM
*Disk space: 15 GB
*GPU (pre-20th): NVIDIA GeForce 6 series, ATI Radeon X1600, Intel HD Graphics 3000 (with 128MB VRAM)
*GPU (post-20th): NVIDIA GeForce 200 series, ATI Radeon 4000 series, Intel HD Graphics 4000 (with 128MB VRAM)
*Direct3D 9.0 compatible video card (with atleast DirectX 8.0 or higher feature level) and 128MB VRAM
*Other: If you play the previous version of the game (from 2010 to 2023, or New Engine pre-20th anniversary) and run on DirectX 8.0 mode or having HDR disabled, the game will have issues with fullbright lighting due to Valve forgot to compile the maps with both LDR + HDR lighting. This issue has been fixed with 20th anniversary update. Also, if your game runs on DirectX 8 level by default, visit this page for fix.
OS X:
*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: 15 GB
*GPU: NVIDIA GeForce 8xxx series, ATI Radeon X1600, Intel HD Graphics 3000OpenGL 2.1 compatible
*Audio: OpenAL compatible
*Other: HDR is required to be enabled (/ branch only)
Linux:
*OS: Ubuntu 12.04, SteamOS 1.0 or laterOther Linux distros supported.
*CPU: 2.0 GHz and/or Dual-core
*RAM: 1 GB
*Storage: 15 GB
*GPU: NVIDIA GeForce 8xxx series, ATI Radeon X1600, Intel HD Graphics 3000OpenGL 2.1 compatible
*Audio: OpenAL compatible
*Other: For / branch, HDR would be required.
== See also ==
* Half-Life 2 level design
* Half-Life 2: Update - a fan-made Steam-released mod aimed at bug-fixing and giving the game a mild visual upgrade. It is no longer recommended for most users since most of the bug fixes have already been fixed in Half-Life 2 itself, and Half-Life 2: Update does not include any new fixes introduced in later versions of Half-Life 2.
* Synergy - a fan-made Steam-released co-op mod that allows users to play the entire Half-Life 2's campaign with multiplayer.
* :Category:Source mods
== External links ==
* 
* 
* on Combine OverWiki
* on Wikipedia
Category:Verified Steam Deck games
Category:Half-Life 2
Category:The Orange Box
Category:Open source mods and games 
Category:Source 2013 SP engine branch games