The infection originated from Hakkar the Wow gold classic Soulflayer -- the boss of this very first 20-player raid Blizzard released. Hakkar would toss Corrupted Blood on gamers and it would damage them for about 10 seconds. Players would disperse the impact to others when they got too close to those infected. Following the 10 seconds were done, or players finished the boss battle, the harmful impact was supposed to end. Only it didn't.

A programming supervision allowed the debuff to spread beyond the website of the Hakkar boss fight and to the world at large. Hunter characters can summon and dismiss pets to fight in their side at will. Once dismissed, all of the consequences on the pets are paused until it's known as back out again. In effect, the pets would contract Corrupted Blood through the boss fight, vanish and then display the symptoms elsewhere in the world map when they were again summoned. There it might spread to other pets and players that came in contact with them.

Cities such as the dwarven city Ironforge and orc town Orgrimmar were overrun in hours. Non-playable characters, who could not die as a result of particular coding, could also capture the consequence, meaning any player that passed by them could get Corrupted Blood.

After word got out, players searched frantically for information about what was going on.

"The entire world chat would burst any time a city fell," says Nadia Heller, an ex-World of Warcraft player whose persona lived through the incident. "We kept a close eye not only on our guild conversation but on world chat too to determine where not to proceed. We did not want to grab it."

The spread of Corrupted Blood, and the player's behavioral changes to this, caught the interest of epidemiologist Dr. Nina Fefferman, who was a World of Warcraft player at the time of this incident. In 2007, the two released a paper that detailed their findings, including complex models of individual behavior in a pandemic. Fefferman claims the episode has helped inform her current research into predictive modeling about covid-19.

"What I really do is study all the aspects of infectious disease outbreaks that help us prepare for pandemics," said Fefferman, a mathematical biologist. "We saw the full gamut of behaviors we find in the actual world reflected from the player characters throughout Corrupted Blood."

Dr. Dmitri Williams, an associate professor from cheapest wow gold USC who was also playing World of Warcraft through the Corrupted Blood episode, questions whether Fefferman's findings are valid mirrors to real-life behaviour.