On World of Warcraft and other games While Blizzard had not intended to create a pandemic event with the Corrupted Blood incident, the company noted the popularity that the pandemic had received. In 2008, Blizzard released an intentional plague in
World of Warcraft to echo the success of the Corrupted Blood pandemic. On October 22, shortly before the release of a
World of Warcraft expansion set titled
Wrath of the Lich King, several mysterious crates appeared in one Azeroth town. Player characters who inspected these crates became infected with an unknown disease, and if they did not find a cure within 10 minutes, they would be transformed into
zombies. Unlike Corrupted Blood, it was possible to cure the zombie infection through healing spells or NPC aid. As the number of infected characters grew, however, the time frame for healing became shorter and the virus became resistant to cleansing. Blizzard put a stop to the Lich King plague on October 28 after receiving complaints from players that the zombie infection was detracting from other parts of the game. Another zombie pandemic known as the Scourge invasion was featured in 2020's
World of Warcraft: Shadowlands expansion. To limit griefing attacks, the 2020 Scourge invasion was designed to make opting into the event more of a conscious choice by players who wanted to fight against the zombie hordes. The Scourge invasion received criticism, however, for its handling of new players.
Shadowlands created a new starting area for players, Exile's Reach, in which new characters were separated from the rest of the game until they reached level 10. While this alternative starting area was isolated from the zombie pandemic, players whose characters began in other starting areas remained susceptible to infection and death. In 2012,
Star Wars: The Old Republic, a MMORPG by
BioWare, released an online disease resembling the Corrupted Blood plague. Characters infected with the Rakghoul Plague would develop a signature cough that became progressively louder before they transformed into a zombie-like creature. Because the plague was transmitted more easily in heavily populated centers, player characters conducted business in more remote business areas to avoid infection. Unlike the Corrupted Blood incident, BioWare intentionally released the Rakghoul Plague, and player characters who succumbed to the disease received special items. Lead designer Daniel Erickson told reporters that the Rakghoul Plague was inspired by the Corrupted Blood incident, but that developers wanted to steer players away from griefing and towards positive interactions with the pandemic. Blizzard closed the Zul'Gurub raid in 2010 as part of a larger update which transformed the region into a five-person dungeon with new bosses. The region was added to
World of Warcraft Classic in 2020, but because
Classic was derived from code created after the Corrupted Blood patch, pets were immune to Corrupted Blood, preventing another pandemic. Despite its accidental nature, the Corrupted Blood incident bore several resemblances to real-world pandemics, leading researchers to explore the event as a disease model. In an article for the journal
Epidemiology,
Ran Balicer of the
Ben-Gurion University of the Negev compared the role that pet companions played in the spread of Corrupted Blood to
avian influenza, which spread through asymptomatic ducks. The use of fast travel to quickly spread the disease between distant locations was also compared to the role that air travel played in the
2002–2004 SARS outbreak. Of particular interest to researchers in the use of MMORPGs for epidemiology is that character responses to a virtual pandemic are the result of individual player reactions, adding "a level of authenticity that doesn't exist in other simulations". Disease researchers typically study disease spread and control through the use of three general models, all of which make significant assumptions about human behavior. As behavior is difficult to predict, the effectiveness of these models is limited. The use of MMORPG environments like
World of Warcraft introduces human behavior into disease models: while player characters are virtual, players are attached to the health and success of their characters and others, creating an immersive social environment. Video game models necessarily include player behaviors that would not be included in a general model. For instance, characters may deliberately enter infected areas in the hope that a healing character would protect them, just as individuals may expose themselves to infection under the belief that a vaccine may be in the region. Some researchers have responded skeptically to the notion that games like
World of Warcraft may accurately model real-world infectious disease patterns. Although Gary Smith, a professor at the
University of Pennsylvania, admitted that mathematical disease models fail to take into account the spectrum of human behavior, he questioned the ability of a video game to remedy this error, saying that "the study is just as 'observational' as disease outbreak studies in the real world". Outside of disease research, some have speculated that the griefing attacks that took place during the Corrupted Blood pandemic may provide a model for
bioterrorism research. Charles Blair of the Center for Terrorism and Intelligence Studies told
Wired that, just as the human behavior in
World of Warcraft supplemented general disease models, the behavior of griefers could augment the computer-modeled tactical decision-making enacted by terrorist researchers. Other researchers noted the similarities between the game and the real-world pandemics. Both had an immediate impact on dense urban areas, which limited the effectiveness of containment procedures in stopping the spread of disease, while air travel, like fast travel, allowed infections to spread across large parts of the world with ease. ==See also==