On September 13th 2005, a very infectious and deadly virus began spreading through the videogame world of World of Warcraft. This wasn't a computer virus that infected your computer, but a literal virus on your computer that affected your game character, and spread from player to player.
I think most people are familliar with World of Warcraft, but in case you dont't know what it is, it's a massive multiplayer online roleplaying game or MMORPG. It basically means that players from all over the world play the same online game together.
It all started with a bloodgod called Hakkar the Soulflayer. He was the endboss in a new World of Warcraft raid arena called Zul'Gurub. Hakkar would steal blood from players to keep up his own health, and the key to beating him was to cast a debuff spell on yourself called corrupted blood. This spell would slowly drain your health and infect the players around you, but it would also make Hakkar vulnerable once he started feeding on your now corrupted blood.
The spell was intended to apply only to the specific area where you fought Hakkar. If a player respawned back into the main world, the corrupted blood spell would dissapear, but because of a coding error this didn't apply to the pets of players. This meant that once players returned to the main world with their pets, the pets would start spreading the corrupted blood to other players, who spread it to others, who then again spread it to others.
Some players were smart. Once people noticed that there was a pandemic going on, they left the cities, characters with healing abilities helped players, and others warned people away outside of the largest settlements..
The game developers at one point even offered a voluntary quarantine, but many didn't follow it, and others even started intentionally spreading the disease.
Actual epidemiologists studied the virtual outbreak to learn how pandemics spread from person to person. It is extremely hard to accurately predict how people respond to a pandemic, and scientitsts are mostly reliant on computer models. The corrupted blood incident allowed them to see how actual people respond in a pandemic like situation.
When the outbreak started many players would travel to infected areas to see what was going on, while trying to leave afterwards without catching the disease, which of course only made things worse. Scientists compared this to journalists in the real world. The game even had asymptomatic carriers in the from of NPCs that could spread the disease, but not die from it.
In the end over 4 million players were affected by the outbreak, and the cities were littered with the bones of dead players!
Of course the incident wasn't a perfect example of how people would behave in the real world when faced with a deadly disease, players in World of Warcraft wouldn't permanently die, and were able to respawn. But still researchers from many different organizations and universities were interested in studying the events that had happened, with even the Centers for Disease Control (CDC) asking the developer Blizzard for statistics on the pandemic.
In the end Blizzard put an end to the pandemic a week later by coding in a patch and doing a hard reset on several servers. Which is a lot easier than developing a vaccine!
Thanks for reading and I hope you enjoyed this story!