Fifteen years ago, World of Warcraft was rocked by an unexpected event known as Corrupted Blood. The boss of the Zul’Gurub raid instance, Hakkar the Soulflayer, had a debuff he could apply to nearby players that caused damage every few seconds. The debuff was designed to kill players quickly enough that anyone without healer support would die fairly quickly.

Unfortunately, Blizzard made a mistake. Hunter pets, if put away while the debuff was applied, would still have it when they were pulled back out again — like, say, in a populated area. That was the first problem. The second problem was that Corrupted Blood was infectious, and spread to people nearby. The third problem? NPCs could catch it. When they did, they didn’t die. They just transmitted it to everyone within range, indefinitely.

Combine ingredients with player ingenuity. Add one penchant for mischief. Distribute thoroughly and you’ve got the recipe for a virtual pandemic. But that’s where, from an epidemiological perspective, things got interesting. It turns out that players responded to these events similarly to how people do in real life.

The event was heavily studied, along with another deliberate outbreak of Undead plague that occurred in 2008, known as the Scourge Invasion / Great Zombie Plague of 2008. The latter was described as being more true-to-life (and remains my personally favorite event World of Warcraft ever held), but the former was more widely studied. And now, 15 years after WoW shipped, that work is actively informing our coronavirus response. PCGamer interviewed Dr. Eric Lofgren, who co-authored the original paper.

“One of the things we are finding, if we look at both Wuhan and Italy, is there’s a huge demand on the healthcare system, and that’s a genuinely serious concern here in the United States,” Dr. Lofgren told PCGamer. “So essentially validating what a bunch of hospitals are doing right now, preparing, and a little bit bracing for the worst.”

It might seem like a stretch — or like the sort of link that WoW-loving journalists might concoct to make an MMO seem important. Lofgren was quick to stress this was not the case.

“For me, it was a good illustration of how important it is to understand people’s behaviors,” he says. “When people react to public health emergencies, how those reactions really shape the course of things. We often view epidemics as these things that sort of happen to people. There’s a virus and it’s doing things. But really it’s a virus that’s spreading between people, and how people interact and behave and comply with authority figures, or don’t, those are all very important things. And also that these things are very chaotic. You can’t really predict ‘oh yeah, everyone will quarantine. It’ll be fine.’ No, they won’t.”

Lofgren is right. I had a serious argument with someone in my own social circle over the weekend, who was declaring that everyone should be going out and socializing as much as possible. According to this individual, the important thing to do is “Show this flu we are not scared.”

Beyond the questionable efficacy of attempting to behaviorally intimidate a virus, this individual was not alone. Ranking GOP Member of the House Intelligence Committee Devin Nunes has declared that people should ignore the quarantine and go about their daily lives:

“If you’re healthy, you and your family, it’s a great time to go out and go to a local restaurant, likely you can get in easily,” Nunes said during an interview on Fox News as many cities announced new restrictions on bars and restaurants to limit gatherings. ‘Let’s not hurt the working people in this country … go to your local pub,’ he added.”

The net effect of listening to Devin Nunes. Also an amusing example of how people used Warlock pets to create their own havoc.

Devin Nunes is wrong. The best way to help the workers of America is for the government to pass laws suspending mortgage payments and other bills, mandating paid sick leave, and providing funding to pay the cost of treating Covid-19 for everyone in the United States. The worst way to help workers in America, particularly restaurant workers who often lack both paid sick leave and insurance in states that refused to expand Medicaid following the passage of the ACA, is not to stay away from them. But studying the contradictory way that people act during a pandemic is quite analogous, it turns out, to studying how people trolled each other on purpose in World of Warcraft back in 2005.

The positive responses people take in response to a pandemic also have in-game analogs. During Corrupted Blood and the Scourge Invasion, people would practice social distancing by avoiding capital cities. In the case of the Scourge Invasion, your chance of getting the infection when someone near you died (and thereby becoming Undead yourself) was a low-chance event in the beginning, with a long timer (several minutes) before you died and plenty of time to find a nearby Spirit Healer to remove the Plague.

As the event wore on, however, both the chance of catching the disease when someone died and the amount of time before you died yourself gradually shrank, while the strategically placed healers that could remove the debuff didn’t get any faster at curing it. The result? Players who clustered at a Spirit Healer hoping to catch a cure (which happened every 30s, IIRC) would die, en masse, before the heal was cast. Attempting to go to the “hospital,” in this case, meant being at Ground Zero as a new wave of Undead ghouls spawned into the world.

But the Scourge Invasion had one interesting twist that Corrupted Blood didn’t. Corrupted Blood was a dimensionless debuff. It had no “type,” which means that virtually no player ability could remove it.

In 2005, the only class that could remove a typeless debuff was Paladins, and only for the length of time that Divine Shield lasted. Once it expired, you had to be out-of-range from reinfection. In 2008, however, the zombie plague was actually a disease — and several player classes could remove diseases.

Thus, even as the plague worsened and the bodies mounted, there were players who would take up station near the overwhelmed NPC Spirit Healers, adding their own removal abilities to the periodic cure that would hit all characters within a certain radius. This, too, mirrors how altruistic people behave during pandemics. Of course, those valiant healers could themselves become disease vectors — if you’re standing near the Spirit Healer when 15 people become Zombies, they’re probably going to eat you, too.

Both of the epidemiologists who studied Corrupted Blood in WoW echoed urgent calls for people to practice social distancing. Stay close to home, wash your hands, and stay safe.

Feature image by WoWHead Classic; in-line image by WoWWiki.

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