Modification

A modification, often abbreviated to mod, is an alteration or creation of files for a game engine, which allow it to modify the gameplay style, graphics, environments, models, etc.

Mods in a broad sense can be a game like Portal Stories: Mel. Mods in the narrow sense add something to the game like Synergy. Some games like Half-Life 2: Update or The Stanley Parable are difficult to define as just one.

Warning:Not every game developer or copyright holder allows mods. Read the End User License Agreements and other related documents. Please note that they may change from time to time.

Types of Mods

• Third-party modifications are mods that has not been developed by the original game designer. Mods are typically third-party, as first-party mods are often called expansions.
• Total conversions (sometimes abbreviated TC) are mods that have altered their original games to such extents (through new models, new animations, new code, among other things) that their original games can no longer be recognized. The amount of work and expertize required for total conversions, makes these types of mods very rare.
• Dead modifications are mods that (often due to loss of interest or internal problems) have ceased development and been abandoned without producing a release.

Installing Source Engine mods

Note:This tutorial may not apply to other mods that was available for download on Steam or mods that comes with an automatic installer.

To install a modification manually, follow these instructions:

Method 1:

1. Copy the mod folder (with the gameinfo.txt file directly inside) into your sourcemods folder. (usually …\Steam\SteamApps\sourcemods), for example:

Windows: C:\Program Files\Steam\SteamApps\sourcemods [for 32-bit Windows] C:\Program Files (x86)\Steam\SteamApps\sourcemods [for 64-bit Windows].

macOS: ~/Library/Application Support/Steam/SteamApps/sourcemods^[confirm]

Linux: ~/.local/share/Steam/steamapps/sourcemods [for normal installation] ~/.var/app/com.valvesoftware.Steam/steamapps/sourcemods [for Flatpak installation]

2. Start/Restart Steam. If the mod is available for play, Steam should list it in your Games library.

Method 2:

1. Copy the mod folder (again, with the gameinfo.txt file directly inside) into \Steam\SteamApps\common\Source SDK Base 2013 Singleplayer or Source SDK Base 2013 Multiplayer folder.

2. Launch hl2.exe with -steam -game "(mod folder name)" command-line parameters. Or you can add the same launch options to Source SDK Base 2013 on Steam games library, then click Play.

Warning:The sourcemods folder must be on the same drive as Steam is installed. If there is insufficient drive space, it can instead be installed manually in the base game's directory.

Installing GoldSrc mods

To install a modification for GoldSrc-based games (such as Half-Life), follow these instructions:

1. Do the same Method 2 as the Source engine, but instead copy mod folder to \Steam\SteamApps\common\Half-Life (for Half-Life) folder.

2. Start/Restart Steam. If the mod is available for play, Steam should list it in your Games library (except in Quake).
OR
Launch hl.exe with -game "(mod folder name)" command-line parameters. Or you can add the same launch options to Half-Life on Steam games library, then click Play.

Note:This methods also applies to many other Quake-based engine games.

See also

• A list of GoldSource (Half-Life) mods and Source mods.
• Help:Mod Profiles - Rules and guidelines for writing new mod articles here.
• Map pack - A pack of maps, which is different from a mod.