WoW’s Corrupted Blood Incident

By Deane Barker on July 2, 2011

Corrupted Blood incident: Back in 2005, a fascinating situation took place in World of Warcraft.  The developers introduced a virus-like spell that was cast by a single bad guy (NPC).  It accidentally ran wild throughout the game world, infecting characters and spreading like a…well, virus.

The Corrupted Blood incident is a video game glitch and virtual plague that occurred on September 13, 2005 in the MMORPG World of Warcraft. The epidemic began with the introduction of the new dungeon Zul’Gurub and its end boss Hakkar, who when confronted and attacked would cast a hit point draining and highly-contagious debuff spell “Corrupted Blood”.

The spell, intended to last only seconds and function only within the new area of Zul’Gurub, soon spread across the virtual world when players discovered that the use of teleportation spells could take the affliction out of its intended confines. By both accidental and purposeful intent, a pandemic ensued that quickly killed lower-level characters and annoyed higher-leveled ones, drastically changing normal game play, as players did what they could to avoid infection.

The spell was cast by a higher-level boss, and the developers intended that it would stay localized around that boss.  However, characters with teleportation tried to get away and unwittingly popped up in places that were free from the virus, and started infecting other people.  (Not dissimilar from when one of the early SARS victims got on a plane and flew from China to Toronto.)

Player responses varied but resembled real-world behaviors. Some characters with healing abilities volunteered their services, some lower-level characters who could not help would direct people away from infected areas, some characters would flee to uninfected areas, and some characters attempted to spread the disease to others – resembling behavior attributed to early AIDS patient Gaëtan Dugas and Typhoid patient Mary Mallon. Players in the game reacted to the disease as if there was real risk to their well-being.

What gets really interesting is that this incident has become a model that real-world epidemiologists have used to study the spread of contagions.