The Mod Squad

Console games like Xbox get the media attention, but PC games are far more intriguing: Whole worlds are rewritten by the players themselves.
Illustration by Nana Rausch

We may earn revenue from the products available on this page and participate in affiliate programs. Learn more ›

Consider whether you would hack a DVD of the film Gladiator so that Russell Crowe was relocated from Rome to, say, a Wal-Mart parking lot in Missoula, Montana. Perhaps substitute pickup trucks for chariots, grizzly bears for lions. Turn the emperor into Osama bin Laden-maybe with no clothes. You might not, but someone would. This is certain because, when it comes to the intricate worlds created for PC-based games, someone does. The difference between games and movies, of course, is that PC games are code worlds, hackable. By cracking and changing the code, players can alter weapons, characters, and, sometimes, entire worlds. They have, famously, inserted Barney into a Nazi shoot-em-up, then gleefully distributed the hacked version on the Internet. They have recreated a scene from The Matrix and inserted it into a hit 2001 adventure game called Max Payne, an action-shooter set in noir-ish New York. More ambitiously, one bunch of hackers is currently busy remaking the entirety of Maax Payne into a flighty fantasy-world homage to a novel by cult author Terry Pratchett.

Alterations of a PC game are called “mods.” Although modifying began among hard-core hackers, it’s not illegal. In fact, mods are often encouraged by game producers. Mods feed an endless appetite for variety and evolution in the gaming world, an appetite no software company could satisfy on its own. Because players must buy the original game CD-ROM to use the (usually free) mod, the original game producer continues to profit. “For a company like ours, the benefits of mods are enormous,” says Gabe Newell, whose company Valve has seen more than 300 mods created for its game Half-Life. “A mod extends the shelf life of the product over time.” Games released several years ago, like Doom and Quake, are still being modified today. Each mod enriches the play. “These people are just ingenious,” says John Romero, co-creator of Doom and Quake. “They have figured out all the weird little bitty tricks in the code that we didn’t even know about.”

Will Wright, creator of The Sims, the game in which players manage the lives of simulated humans, noticed that hackers began to modify his game as soon as it was released in 1999, creating mods (or patches, as they’re also called) that would, for example, render all the characters nude. “If you look at the amount of stuff fans have created for the game,” says Wright, “it probably outnumbers the stuff we’ve created, 9 to 1. I think it’s great.” Diabolically, Wright introduced his own mod to The Sims in 2000, a wee Trojan horse in the shape of a guinea pig. If not properly cared for, the rodent spread a deadly virus to its owner, a plot twist that Wright did not disclose until many characters were in their virtual graves.

Though it began on the fringes of the Internet, the mod community has moved toward the center of the game industry, drawn by the pot of gold that lies there. Inevitably, community and commerce became entangled, and accusations about selling out fly. Smack in the middle of things are John Cook and Robin Walker, college buddies who are riding their mod success into mainstream business success. Six years after they distributed Team Fortress, a hit modification of the computer game Quake, for free on the Web, the duo is preparing a long-awaited-very long-awaited-sequel, Team Fortress 2: Brotherhood of Arms. The difference between then and now: The sequel will be sold. TF2 could find more players than the game it modified-and take a big bite of the $10 billion that fuels the gaming industry.

The culture of mod making grew out of what author Steven Levy famously described as the hacker ethic, which predated the explosion of Internet culture and emphasized “sharing, openness, decentralization, and getting your hands on machines at any cost.” When it came to software, games were ideal hacking material: creative objects whose DNA was ripe for sharing and mutation. The first notable mod was a variation on a text-based computer game. Boston programmer Will Crowther created the original version in 1972 as a way to combine his interests in fantasy role-playing and spelunking. Four years later, a hacker at Stanford, Donald Woods, politely asked Crowther for permission to modify the program a bit, and the result, Adventure, gave rise to a craze. Students and hackers in computer labs across the country began playing and modifying text-based games, usually basing their mods on Dungeons and Dragons or Star Trek.

A decade later, mod making broke into the down and dirty world of arcade games. In 1981, three MIT students, Doug Macrae, Kevin Curran, and John Tylko performed a digital sex-change on Pac-Man. They added a pink bow to the yellow dot, and threw in some new fruit. The result, Ms. Pac-Man, was sold to a national distributor and became a monster arcade hit.
In the mid-1980s, early Mac aficionados discovered that by using a free program called ResEdit they could easily modify the game Crystal Quest, in which players zoomed around outer space, picking up glowing crystals and fighting off hostile aliens. In one popular mod, the game’s sounds were replaced with sexually explicit moans and groans.

This barely foreshadowed the tremendous impact of Doom, a seminal game released in 1993 by a company called id Software. Doom invited the mod community into the tent. John Carmack, lead programmer, was a hacker who, as a teen, cracked open games to give his characters extra skills. Carmack became intrigued by the emerging mod phenomenon when he saw that someone had hacked the code of id’s early shooter, Wolfenstein 3D, and replaced the Nazi bosses with dancing purple Barneys. Many versions of the Wolfenstein Barney Patch can still be found on the Web. “Ever since then,” says Carmack, “it’s been one of my highest strategic decisions to make all these things possible. Putting these capabilities into the hands of the users, the game becomes a new canvas for people.”

For Doom, a game in which players race through maze-like levels to acquire weapons and treasure while killing assassins and monsters, Carmack organized the code so that players were at less risk of damaging the core game when they introduced new sounds, graphics, and levels. He did this by creating a subsystem that separated the sound and picture “wads” from the core code that governed gameplay. Every time someone booted up the game, the main program would look for the wad of sounds and images to load in. The mod writer could simply point the main program to the new wads. Carmack also made available the source code for the Doom level editing and utilities program to give mod makers powerful tools.

This was a radical idea not only for games but, really, for any type of media. Although some level editing programs had been released in the past, few programmers-let alone owners-of a company had released the guts of what made their products work. It was an ideological gesture that empowered players and, in turn, loosened the grip of game makers. It was also, as it turned out, mighty good business.

Weeks after Doom’s release, hackers began creating level editing programs. These tools let players change existing rooms in the game-relocate walls, move floors, or make other minor adjustments. Soon, two students collaborated to release the Doom Editor Utility, which explained how to build a level from the ground up. “You can do almost anything to any level,” they pointed out, “move, add, or remove monsters and power-ups, change the wall colors and positions, create new lifts, doors, acid pools, crushing ceilings . . . or even create a new level from scratch!” For the hard-core Doom player, the ability to create new acid pools was pure joy.

The Doom Editor Utility was a watershed in the evolution of the participatory culture of mod making. Anyone with the interest could create a level of a complex game, the equivalent of writing a new chapter into a book, and then, via the Internet, publishing that creation. The tools let the player tweak what was there, or dress the game up with sounds, images, or ideas. The mod maker didn’t need to be a hard-core programmer or an artist. Soon a University of Michigan student named Greg Lewis dived deeper into Doom code and came up with a program called DeHackEd, which allowed a user to modify not the wads but the game’s core code, the executable file. Mod tools turned game players into game makers. Soon, the mod makers were swapping their Doom levels for free in forums on AOL, CompuServe, and across the Internet. Gamers who had been flunking out of school because of deathmatching now had an even more addictive pastime: all-night hacking parties.

Like a lot of mod makers, Cook and Walker remember precisely where they were when Quake hit. It was the fall of 1996, mid-semester at the Royal Melbourne Institute of Technology in Australia. Both men were computer science majors. As the follow-up to Doom, Quake promised to be even more open for modification. “We started to think about creating a mod that would work around the concept of social interaction of players,” Walker says.

Using source code for Quake that had been made available over the Internet, Cook and Walker went to work. The result was Team Fortress, a mod based on the concept of cooperative multiplayer team action. In the online version of Quake, players shot at each other one-on-one; Team Fortress created an environment that was a step closer to real warfare. Players could choose from nine character classes, ranging from snipers to medics, then compete in rival factions. The introduction of character skills brought a new depth to the shooter genre. Players behaved according to their class. “You were doing more than just stealing a team’s flag,” says Sal Accardo, senior PC editor for Gamespy, a leading gaming site. “Team Fortress gave players a chance to find what they do well.”

Cook and Walker didn’t form a company to sell their finished product. They did what any other mod maker would do: They released the game online, downloadable for free. The success was extraordinary. Soon other mod makers around the world began contributing to the Team Fortress world, creating special character appearances, called skins, and game levels, called maps. These were, essentially, mods of mods, serially and collaboratively hacked. Nearly 1 million people ended up downloading Team Fortress. Soon, nearly half of the Quake games being played online were Team Fortress.

Across the ocean in Seattle, a start-up game developer called Valve took notice. Valve itself was something of a mod team with a business plan. Instead of making a modification based on limited code, Gabe Newell, a former Microsoft Windows development leader, decided to license id’s complete programming core “engine” for Quake. A mod, though legal, could not be used for commercial purposes except with the permission of the game’s creator. With a license, Valve could sell its game like any other.

Released in 1998, Valve’s Half-Life, a science fiction first-person shooter, was hailed as a breakthrough-a game using a mixture of old and new code that offered a fresh story and emotional wallop. Cook and Walker, of course, immediately created a mod of Half-Life. The result, Team Fortress Classic, was downloaded by 3 million people worldwide.

Valve liked Team Fortress so much that it offered Cook and Walker a business deal: The company will release Team Fortress 2 as a full-fledged retail product. Long delays in the release of TF2 have generated Web sites filled with feverish speculation about what the game will look like, and when it will arrive (the company now says it will be sometime next year). Not surprisingly, the commercial aspect of the TF2 mod has also ignited controversy within the hacker community over whether or not it constitutes a sellout, and whether Valve, which aggressively markets mods of its games, hurts or helps the culture. “The whole point of making a mod is to be free and not have some company telling you what to do,” says Chris Rogiss, a programmer who worked on the popular Quake mod, Urban Terror. On the contrary, says Tom Mustaine, a mod maker whose work led to a full-time job at Ritual Entertainment, a game company: “The secret desire of every mod creator is to get recognition from the companies who are making the games.”

Jordan Edelson, aka Master X, would agree. A 17-year-old junior at Horace Greeley High School in Chappaqua, New York, he’s directing 21 people-artists, animators, sound engineers, game testers, and programmers fluent in the C++ computer language-in the creation of a Half-Life variation called Xmod. Edelson wrote the story line (human mutants created as supersoldiers by the U.S. military escape their compound; all hell breaks loose) but what’s truly original about his mod are its add-on features: an in-game virtual PDA that offers advice and helps locate teammates, an 18-song original soundtrack, the ability to mix and match attributes to create your own character. Edelson and his all-volunteer team have been toiling for more than a year now, and by sharing early, unfinished versions have already gained a sizeable following on the Internet. “You can pretty much go anywhere you want with it,” he says. “I like working with other people and trying to create something that has the possibility of being bought out by Valve or another company.”

Not all game companies are open-minded about mods. Console manufacturers like Sony, Microsoft, and Nintendo, which rely on game-disc sales and fear knockoffs, have yet to create a means for gamers to get under the hood of their titles, though that doesn’t stop them from trying. Microsoft’s PC-code-based Xbox, in particular, has the hackers salivating.

No matter the barriers, the advantage probably lies with the modifiers in the long run. They are persistent and they are creative. “With what we make,” Cook says, “the story never ends. They’re living products.”