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 . Mods in the narrow sense add something to the game like . Some games like or are difficult to define as just one.
== 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 (or DLC, short for Downloadable Content). Third-party mods usually runs on Source SDK Base, but some mods might run on top of or other games.
**Content-only mods (which includes Steam Workshop addons) are mods that simply replace the original game assets (such as replacing models, textures, sound, etc.), without changing any game code.
*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 ==
To install a modification manually, follow these instructions:
===Method 1:===
:1. Copy the mod folder (with the file directly inside) into your folder. (usually ), for example:
::: [for 32-bit Windows] [for 64-bit Windows].
::: 
::: [for normal installation] [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 file directly inside) into or folder.
:2. Launch hl2.exe with command-line parameters. Or you can add the same launch options to Source SDK Base 2013 on Steam games library, then click Play.
== Installing GoldSrc mods ==
To install a modification for -based games (such as ), follow these instructions: 
:1. Do the same Method 2 as the Source engine, but instead copy mod folder to (for ) folder.
:2. Start/Restart Steam. If the mod is available for play, Steam should list it in your Games library (except in ). ORLaunch with command-line parameters. Or you can add the same launch options to Half-Life on Steam games library, then click Play.
== Install content mods ==
=== Source ===
To install content-based mods, such as custom models, texture, audio, etc. for Source games, follow these instructions:
;Steam Workshop
:Simply click "Subscribe". Some games may require restart to download addons.
; VPKs
:Drop to 
; (and above) VPKs, aswell legacy addons/folder-based addons.
:Drop to folder
:: 
; Folders (containing , , , etc. inside it)
:Drop to 
:: 
: Overwrite game files
:: Old method for games that simply doesn't support above methods. Simply overwrite files in with one from the zip. Note that this method is no longer recommended for -based games.
=== GoldSrc ===
To install content-based mods, such as custom models, texture, audio, etc. for GoldSrc games, follow these instructions:
: folder - Simply create the folder, with the game name on it, and ends with (example: for ), then put your custom texture (WADs), models and/or sound there.
:: This is only available on GoldSrc games post-SteamPipe.
: Overwrite files - Simply overwrite files in with one from the zip. Note that this method is no longer recommended for updated 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.
Category:Files
Category:Glossary
Category:GoldSrc
Category:Source