On September 13th, 2005, the Presidents of the United States and of the People’s Republic of China met to honor the United Nations’s 60th anniversary. Americans were listening to Kanye West’s “Gold Digger” while UK citizens pushed “Don’t Cha” into the Top 5. Virgos around the globe were celebrating their birthdays. And in the virtual world of World of Warcraft (WoW), a global pandemic had just begun.

With the introduction of a boss fight restricted to only high-level players, a new game mechanic was implemented through “Hakkar the Soulflayer”’s special attack. When the hit-point (HP) draining and highly contagious “Corrupted Blood” spell was cast on a player, they lost a few health points and had to pause in fighting to recuperate. However, as they hung back to preserve themselves, any player standing near them would also contract the “Blood” and bear the effect as well. It may be annoying, but it’s not devastating; the only people affected were high level, high HP-bearing players. That’s why, when leaving the fight, the players are wiped of the debuff to keep it from infecting the outside world.

However, when the fight was implemented, Blizzard developers made one fatal mistake: while the players were wiped of the effect, pets and non-player-characters (NPCs) weren’t. Thus, Corrupted Blood found a home in the general player base.

The Washington Post first compares the NPCs’ and pets’ roles in spreading the Corrupted Blood to how rats spread the Bubonic plague in the 14th century, which expresses one way WoW’s pandemic models real-world epidemiological models. Game Theory, a gaming Youtube channel with 15 million subscribers, notes, “[The NPCs acted] as asymptomatic carriers; having the debuff, but not showing any outward signs of their infection… they were invisible vectors.”

This also models the way COVID-19 was spread throughout our world, as roughly 40% of infected Americans are asymptomatic, according to Dr. Anthony Faucci. These people can be contagious for up to 20 days. The coronavirus, like the Blood plague, spreads silently.

Additionally, the Blood disproportionately affected lower-level players. They had less HP, meaning that it took less time for the debuff to wear away their bank of health-points, leading to quicker, or, for some, instantaneous death. This inequality in the way members of the player base were affected mirrors COVID-19’s nature of harming older people more than it does young. 

Along with Corrupted Blood mimicking the spread of epidemics, it also reflects human response to them. One example of this is how easily Corrupted Blood spread to densely populated cities, just like how New York (27,399.60 people/sq mi) and other metropolitan areas became hotbeds for the virus. Certain players acted as doctors/nurses by using their healing powers to cure players in need while griefers actively spread it among populations, similar to the effects of anti-maskers’ behavior. 

Real-world government response is also eerily similar to how Blizzard (the company who owns WoW) responded to the pandemic: by trying to quarantine infected areas, just like how international flight was cut off and people were made to stay in their homes. Additionally, as in the real world, it didn’t completely stop the spread. This proves that, whether in simulation or reality, “Once a fully contagious virus emerges, its global spread is considered inevitable,” as noted by the International Monetary Fund in a 2007 report (qtd in Marshall). In the end, over two million players across three servers were infected.

Through eerie parallels to the spread of real viruses and human response to them, the Corrupted Blood plague offers a useful pandemic model epidemiologists can never recreate with a computer; this is because it includes data outlining the influential role of human participation in pandemic-spreading. Prof. Nina H Fefferman and Dr. Eric Lofgren, two epidemiologists, argue this in a 2007 report on WoW’s pandemic. “…[A]ppropriate exploitation of these gaming systems could greatly advance the capabilities of applied simulation modeling in infectious disease research.”