Video game modding

Video game modding (from "modifying") is the process of player and fan-authored alteration of a video game and is a sub-discipline of general modding. A set of modifications, called a mod, can either alter an existing game or add user-generated content. Modders, people who mod video games, can introduce a variety of changes to games, including altering graphics, fixing bugs, and adding unique gameplay elements. Mod development uses official or user-made software development kits, distinguishing it from in-game creations. Modding a game can also be understood as the act of seeking and installing mods to the player's game.

People can become fans of specific mods and can involve themselves in the process of mod development and discourse. In cases where modding is popular, players use the term vanilla to describe the unmodified game (e.g. "Vanilla Minecraft").

Mods that extensively transform gameplay are known as total conversions, with some developing into distinct games. As early as the 1980s, video game mods have also been used for the sole purpose of creating art, as opposed to a playable game, leading to the rise of artistic video game modification, as well as machinima and the demoscene.

With tens of thousands of mods created for popular games, the proliferation of video game modding has made it an increasingly important factor in the success of many games. Modding extends the replay value and interest of the game.

A specific date of origin for video game modding has not been agreed upon by historians, partly due to discussion over what constitutes a mod and partly because of insufficient historical documentation. However, the very first computer games already were being actively modified by the first generation of hackers, and researchers have described modding as an evolution of the hacker culture which pioneered the video game industry.

Widely considered one of the first computer games, the 1962 game Spacewar! was distributed freely as testing software for the PDP-1, an early computer. The game was a result of hardware and software experimentation, supported by the programming culture at the Massachusetts Institute of Technology (MIT). On university campuses where the computer was installed, programmers continued to experiment with the game by modifying it heavily, allured by the prospect of fixing a "dire problem [...] as easily as changing a few instructions", as Steven Levy describes. Their efforts resulted in a wave of improvements to Spacewar!, from changing aspects such as gameplay physics to creating new graphics. The final version of the game was ultimately a product of a group effort of hackers, who contributed to the game without pay. In this way, Spacewar! was not only the first video game, but also the first video game to be modded. On the popularity of hacking Spacewar!, Levy reflected:

Like any other program, it was placed in the drawer for anyone to access, look at, and rewrite as they saw fit. The group effort that stage by stage had improved the program could have stood for an argument for the Hacker Ethic: an urge to get inside the workings of the thing and make it better had led to measurable improvement. And of course it was all a huge amount of fun.

Other early video games also released as iterations of collaborative improvements. Colossal Cave Adventure, a text adventure game developed by Will Crowther and released in 1976, was greatly expanded upon by Stanford graduate Don Woods. After receiving the source code to the game from Crowther, Woods increased the game's complexity and released a modified version in 1977 to instant success. The desire to improve software—the "hacker ethic", as described by Levy—became a crucial factor to the emergence of modern modding culture.