The Corrupted Blood incident on World of Warcraft has become the stuff of internet legend.
OPINION: When a game is one of the most popular and profitable on the planet, and the biggest online role-playing game in history, an unplanned virtual plague, highly infectious and extremely deadly, really makes news.
It started innocently, with game studio Blizzard adding an official content update in September 2005 that included a new high-level dungeon with a super-tough final boss. One of this boss's special abilities was an effect called Corrupted Blood. It was what's known in online RPG circles as a "de-buff", a lasting condition that incurs a negative effect, in this case a rapid loss of health, but it was extra dangerous because it could be passed from character to character like a virus. For high-level characters it was little more than an annoyance, short-lived and easy enough to cure.
There was a problem, though. The effect was meant to be contained to just that dungeon, but when players teleported out, such as by jumping straight back to a town, the disease was passed on. For a lower-level character, the loss of health could be devastating, and new players would be dead in moments. Even worse, computer-controlled characters, such as shopkeepers, could be infected without suffering any health loss, making them asymptomatic carriers.
The infection swarmed across WoW killing untold numbers of characters. Many realised that crowded urban areas were high risk, so fled to the countryside, leaving behind cities full of corpses. Some attribute at least some of its rapid spread to malicious players who deliberately contracted the disease and teleported into busy areas, hoping to spark a local epidemic. What happened next was the fascinating part. The community response took on remarkable similarities to authentic disease-control scenarios, with players instigating quarantine procedures, volunteering as doctors, and setting up emergency medical centres.
Out in the real world, academia started to take notice. The incident was studied as a virtual model of how real diseases spread, with international air travel taking the place of magical teleportation, and other researchers studied the culture of deliberate infections to model the way terrorist cells operate. Both topics have been the subject of serious academic research.
There were echoes of Corrupted Blood in Blizzard's official a deliberate plague in 2008, a Halloween special known as the Great Zombie Plague. Promoting the upcoming expansion pack Wrath of the Lich King, zombies appeared all over WoW, and players could become infected and turn into zombies themselves. Owing to a far lower infectivity rate, the incident did not blow up to anything like the scale of the accidental plague of three years earlier, but it still exhibited similar spread patterns, and epidemiologists were once again fascinated.
This month, the Borderlands series has been struck by its second digital disease. Hackers using unauthorised means to boost their characters' abilities in the Xbox 360 version have accidentally engineered a highly infectious "virtual plague" that can, in extreme cases, result in characters being permanently "killed", their save file deleted. There is no indication the infection has been picked up until the character dies during combat in the game, and instead of reappearing at a respawning station remains permanently gone. Even worse, due to some quirk of the game this glitch can very easily be passed from character to character when they play together in online games, and players can unknowingly pass it on to others.
The effect is disturbingly similar to the spread of sexually-transmitted infections in the real world. People who consider themselves to be safe because they only play online with the same trusted group of friends can all be infected if just one of their friends plays online with a random player and inadvertently brings the glitch back to the group. This mirrors real-life events, when one partner in a relationship has an affair, and unknowingly brings an STI home. Art can sometimes imitate life in unsettling ways.
Players of the original Borderlands had a similar but less destructive experience when players using hacking tools to modify their characters accidentally created a bizarre piece of gear that could not be put down. The shield device would reappear after being sold, jump back into a character's inventory after being dropped on the ground, and could even delete other pieces of gear in the process.
In both cases, Gearbox swiftly identified the problem and rushed out a patch.
While these kinds of virtual plagues can be annoying for players, in extreme cases severely hampering their ability to enjoy their game, they are a fascinating phenomenon, and a reminder of the unique nature of video games. We have never seen issues like this before, because we have never had interactive, inter-connected media like this before. It makes me wander what other surprises games still have in store for us.