Game Modding Culture: From Spacewar! to Dota, Counter-Strike, PUBG
The history of modding, where players rework games into new ones: hacker roots, Doom WADs, Counter-Strike, Dota, battle royale, Auto Chess, paid mods.
A game "mod" comes from the English word modification and refers to changes or new content that players or fans add to an already released game. The range is wide, from small tweaks that change the graphics, to patches that fix bugs, to "total conversions" that turn a game into an entirely different genre. In games with an active modding scene, the unmodified original is sometimes called "vanilla."
Mods never stayed a mere hobby. Several of the genres that hundreds of millions of people play today were born from mods. In this post, we look at how modding culture began and became an important current in the game industry.
Modding Began with Hacker Culture
Historians do not agree on exactly when modding began. Opinions differ on what counts as a mod, and the records are incomplete. What is clear, however, is that even the very first computer games were already being modified.
Spacewar!, created at MIT in 1962, was distributed freely, much like a test program for the PDP-1 computer. Programmers at universities where the computer was installed modified the game as they pleased, adding countless improvements from physics to graphics. Journalist Steven Levy described this as the "hacker ethic": the desire to look inside a program and make it better became the root of modding culture.
The text adventure Colossal Cave Adventure, created by Will Crowther in 1976, was similar. Stanford graduate student Don Woods obtained the source code from Crowther and released a greatly expanded version in 1977, which became hugely popular.
Home Computers and Castle Smurfenstein
As home computers such as the Apple II and Commodore 64 spread in the late 1970s, mod makers expanded beyond universities. There were no official tools at the time, so people opened up files and, through trial and error, swapped in their own graphics and stages.
A representative example from this period is Castle Smurfenstein. Two high school students replaced the enemy characters of the 1981 Apple II game Castle Wolfenstein with characters from the cartoon The Smurfs, and it is often cited as a pioneering example of modding culture.
Doom and WAD Files: A Game Designed for Mods
The decisive game that popularized modding culture was id Software's Doom in 1993.
Fans had already made mods for id's previous game, Wolfenstein 3D. One mod even replaced the final boss with Barney, the dinosaur from a children's TV show. Some employees worried about copyright issues, but developers John Carmack and John Romero welcomed it. When Carmack designed the next game, he made it easy to mod from the start.
Doom separated the game engine from its data (maps, graphics, sounds), storing the data in "WAD" files. Mod makers could simply create and distribute their own WAD files without overwriting the original game. Since they didn't need to share the original data, copyright issues were reduced as well. Around launch, id released source code related to map editing, and in 1997 it released the full Doom source code.
At the time, the game industry was strongly protective of intellectual property, so id's attitude was very new. In return, id made mods work only in the full retail version, not the free shareware version, so that mods also led to game sales. Final Doom in 1996 included fan-made stages, and their creators received a share of the revenue. In 1995, id hired Tim Willits, who came from the Doom modding community; he later became a studio director at id's parent company, ZeniMax Media. Mods had become a gateway into the game industry.
Games Born from Mods
From the late 1990s, mods began producing standalone games and even new genres.
Quake and Half-Life: Team-Based Shooters
Quake mods "Capture the Flag" and "Team Fortress" became staple modes of later shooters. Team Fortress later led to Valve's Team Fortress 2.
In 1999, Minh Le (Gooseman) and Jess Cliffe began making Counter-Strike, a Half-Life mod depicting a battle between terrorists and counter-terrorist forces. When it became hugely popular, Valve bought the intellectual property and released it as a full game in November 2000. Day of Defeat, set in World War II, followed the same path.
From StarCraft Custom Maps to Dota and the MOBA
The "custom map" (use map settings) culture familiar to Korean players is also a branch of modding. Blizzard included a campaign editor in StarCraft in 1998, and one of the maps made with it was "Aeon of Strife." Instead of managing many units and buildings, you controlled a single hero and fought waves of enemies.
In 2003, a creator called "Eul" used the Warcraft III World Editor to develop this idea into Defense of the Ancients (DotA). DotA-Allstars, which gathered heroes from various creators, followed, with Steve Feak (Guinsoo) and IceFrog leading development in turn. Dota is regarded as the most important inspiration for the MOBA genre. Valve hired IceFrog in 2009, acquired the rights to Dota, and released Dota 2 in 2013, while Feak joined Riot Games and took part in developing League of Legends.
From DayZ to PUBG
DayZ, a zombie survival game that Dean Hall made in 2012 as a mod for the military simulation ARMA 2, attracted more than one million players in four months. Hundreds of thousands of people even bought the original ARMA 2 just to play the mod.
Brendan Greene, a DayZ player, created DayZ: Battle Royale under the name "PlayerUnknown," a mod in which players fight until only one survives. He later added elements such as starting by jumping out of a plane in a battle royale mod for ARMA 3, and in 2016, at the invitation of Korean game company KRAFTON (then Bluehole), he moved to Korea and led the development of PUBG: Battlegrounds.
Auto Chess and the Auto Battler
In January 2019, China's Drodo Studio released Dota Auto Chess as a custom game for Dota 2. In it, heroes placed on a chessboard fight automatically; it attracted more than 8 million players by May 2019 and quickly created the "auto battler" genre. Dota was itself a mod, and yet another new genre emerged from a mod of that Dota.
| Original game | Mod | Resulting game / genre |
|---|---|---|
| Half-Life | Counter-Strike | Counter-Strike series |
| StarCraft → Warcraft III | Aeon of Strife → DotA | Dota 2, League of Legends, MOBA genre |
| ARMA 2 / 3 | DayZ, battle royale mods | PUBG: Battlegrounds, battle royale genre |
| Dota 2 | Dota Auto Chess | Auto battler genre |
| Half-Life 2 (Source engine) | Garry's Mod | Standalone sandbox game |
The Era of Official Tools and Mod Platforms
Once it became known that mods could drive success, companies began releasing modding tools alongside their games. From the mid-1990s, PC games often included editing tools, and one count found that in 2003, eight of the ten best-selling PC games included modding tools.
- Bethesda's The Elder Scrolls series: Skyrim has countless mods made with the official Creation Kit. Starting with the Special Edition released in 2016, mods became available on consoles as well.
- Nexus Mods: Started in 2001 as a Morrowind fan site, it is now a leading mod distribution site. As of April 2026, it has more than 73.3 million registered users and supports more than 4,500 games.
- Steam Workshop: A feature within Valve's Steam that lets you find mods and install them with a single click. It greatly lowered the barrier to finding and installing mods.
The Paid Mods Controversy
Can mod makers be paid for their work? This question sparked major controversy in 2015. In April 2015, Valve introduced paid mods to the Steam Workshop, starting with Skyrim. Mod makers received 25% of sales revenue, with the rest split between Valve and Bethesda.
The backlash was fierce. Problems erupted all at once: having to pay for mods that had been free, excessively high prices, mods uploaded without the original creator's consent, and mods containing other people's copyrighted work. Some paid mod makers even received threatening comments. More than 130,000 people signed a petition demanding the feature be removed, and Valve scrapped it within a week and issued refunds. The incident showed that modding culture rests on a community spirit of "gifting and sharing." Since then, various attempts have continued, such as officially curated mod sales and donation models.
What Mods Left the Game Industry
The influence of modding culture can be summed up in three main points:
- A laboratory for new genres: Ideas that big companies would not try, such as MOBAs, battle royales, and auto battlers, were proven first in mods.
- A training ground for developers: Many mod makers, such as Tim Willits of Doom, Minh Le of Counter-Strike, and Brendan Greene of PUBG, became central figures in the game industry.
- Extending game lifespans: Thanks to mods, even old games get new content and their communities carry on. This is one reason games released more than ten years ago are still widely played.
The fact that many games today include level editors or creative modes by default is also a result of this trend. "Making things yourself" has become another way for players to enjoy games.