- This article is about modifying game files. For the garages that modify vehicles in Grand Theft Auto: San Andreas, see Mod Garages.
A modification is an alteration to a game. Grand Theft Auto modifications are created by fans after the game's release, and are not authorized or endorsed by Rockstar Games. Modifications can be obtained from many Grand Theft Auto websites and fansites.
Almost all modifications are entirely free, and may be downloaded and used by anybody. However, there are restrictions on editing and distributing the modification, so always ask permission from the author.
Modifications are mainly only used on PC versions of Grand Theft Auto games. There are methods of modifying console versions, but these are complex and usually break the license agreement of the game and games console.
Different Types of Modifications
Modifications in special websites usually are distributed on several categories, depend on aspect of game they changes:
Maps - modifications of this type add buildings, islands, towns and other objects to an existent landscape of the GTA game. They consist of the added model description with corresponding textures and collision data. Examples are Pleasure Island mod for GTA Vice City and WTC Modification for GTA San Andreas.
Missions - modifications of this type alter or replace the mission script (main.scm in all of the GTA III Era games) of GTA game. These could alter details of missions or even add entirely new missions. The mission script file is responsible for what-happens-when, so modifying it can achieve almost any effect.
Patches (fixes) - modifications of this type do not change anything appreciable but only correct errors present in the original GTA game, like DFT30 missing rear wheel in GTA San Andreas and wrong placed Cuban Outfit in GTA Vice City. Some of modifications attempt to restore hidden features in game: Ghost Town in GTA III, scenes for adults in GTA San Andreas.
Player (clothing) - modifications of this type change protagonist model in game, add or replace available clothing items, sometimes also offer new animation or voice data for the player. Creation of modifications of the given type began after release of the GTA III, the first GTA game contained appreciable protagonist model. Pedestrians modifications also often appoint to the given category.
Vehicles - modifications of this type add a new cars, boats, planes & helicopters to a GTA game, or change existent vehicles colors and handling, sometimes even replace certain cars with new hi-poly modelled and textured version of them. This is a most popular kind of modifications (as also the lungs for realization), often united in large thematic packages.
Weapons - modifications of this type alter weapons models and data, like accuracy or rate of fire, and sound of shooting. They also usually provided as thematic packages.
Some modifications encompass many of these features at once - these are known as Total Conversions (TCs). TCs generally change everything in that GTA game, including the map, vehicles, pedestrians, players and missions. A few TC mods been made, and there have been many more planned that have never reached a release. Most of TCs made for the GTA San Andreas, that is explainable by the time of occurrence of ready tools for development in all aspects and growth of a community. Examples are notorious Grand Theft Auto: Great Britain, Grand Theft Auto: Criminal Russia and GTASA: Liberty City, all are still in development for the Grand Theft Auto: San Andreas.
Not a modifications
Some third-party programs wrongly count as modifications. The basic criterion for modification is changing the original game 'content' files, and this programs actually do not touch that files.
Trainers, which is a programs that runs alongside the GTA game and manipulates the game's data stored in memory. These programs can change many different things, ranging from the player's health, armor, weapons, skill and even location; to being able to spawn vehicles, modify the current vehicle (e.g. color, damage etc) and edit vehicles stored in garages; to modifying the time, game speed and weather.
Multiplayer. As all PC versions of the GTA III Era games lacks any forms of multiplayer capabilities, gamer community start creation of unofficial multiplayer clients & servers. These programs allow to play online with other players on public servers, or offer 'head-to-head' competitions between directly connected players. Types of gameplay provided may differ between different realizations, but usually are versions of FPS-like deathmatch/CTF or rally/street races. Examples are Multi Theft Auto, Vice City Multiplayer and SA-MP.
Enhancers are additional programs/libraries which remove or increase certain GTA game engine limits and restrictions, like maximum draw distance and number of objects in scene. Display of these restriction are well known drops of road texture, delay of LOD textures on buildings when moving fast and traffic unification with current protagonist car driven. Some of enhancers also apply modern shader post-processing effects to game graphics. Noted enhancers are SA Limit Adjuster and ENBSeries tweakers.
Some things, like car colors and handling, weapons characteristics, ped relations, can be changed easily because all the data necessary stored in plain-text files, with basic guidelines for their usage from game developers in file headers. However, creating more advanced modifications (such as entire buildings or cars) is trickier, and usually requires some advance experience in creating models for games. Google SketchUp is a good program for creating building models. 3DS Max, Lightwave and Zmodeller are also used. Textures creation is also not so simple, textures must match with specific game engine limitations and should be organized by special order into TXD files.
The mission modifications are even harder to produce. First, mission script for game must present in compiled form, which require use of special compiler/decompiler tools for any changes. Second, script language not officially documented, worse, each script editor have own interpretation of it. Finally, many script features depend on hardcoded functions in game executable, which can lead to unexpected troubles with different usage approaches, game region versions, official patches and even dependences on end-user hardware. These results with mission modifications are usually simple gameplay missions. Most often used mission script editor is Mission Builder by Barton Waterduck and its derivative, Sanny Builder.
For Total Conversions, even more specific tools needed, like ped & traffic paths editor, GXT (texts) editor, interface (menu) editor and so on. It is strongly advised that you do not attempt to do more than you are capable of. Do not expect to be able to recreate your favorite car in a few hours, many modifications take months.
Vehicles, player and weapons modifications are usually constructed on replacement of already present game objects, because there are limits to number of objects of such kind in game engine, often already filled up by developers, and addition of the new model will require a lot of 'precision' editing in many game files. Therefore, the new car, weapon or clothes will replace existing one and all installation is reduced to work with IMG archives and little editing of one or two game files in text editor. Always do backup of files touched before any changes occurs!
Installation of larger modifications, such as maps, depends on a method chosen by the developer of mod. Some mods are made as file replacements, mod comes in form of archive which you must unpack to original game`s directory. This simplified installation cost large files to download. Other mods come with special installers (mod installers), which automates work with IMG archives and text-files editing. Both methods usually uncompatible with other mods present, so you must install them over special fresh installation of the original game.
Some gamers consider modifications to spoil the integrity and theme of the game - for example, they don't think a 2005 Lamborghini belongs in a fictitious 1990s world, although you can make your own decisions on these matters.
Most modifications do not alter the status of your game. However, if you install a modification that edits or replaces the mission script file, you will have to begin a new game (except in rare cases), or use a provided savegame created for that specific modification. The game will crash immediately if tried to load an old savegame file.
Modifications that were badly coded (mainly missions) or contain many hi-quality textures and models may results with game performance degradation, jerky framerate and various graphical glitches, especially on old hardware.
You modify your game at your own risk. There is no guarantee that all modifications you download will work, or whether the instructions will be complete. You should make yourself familiar with simple well-known modifications (such as cars) before attempting to install larger and more complex models.
Always read the instructions thoroughly, and always backup files before you edit