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.