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.