9. Corrupted Blood (World Of Warcraft)
In 2005, WoW was patched to include a new multiplayer raid – Zul’Gurub – which tasked
players with overcoming a new adversary, Hakkar the Soulflayer, armed with the
powerful enchantment, Corrupted Blood.
The spell was incredibly overpowered, but restricted by the developers to a certain area – which players soon overcame using pets and minions, allowing them to carry the plague beyond the confines of Zul’Gurub into the over world.
The result was a virtual epidemic, permitting some players a massive advantage in combat – annihilating players in a single move – which programmers attempted to contain by quarantining massive portions of the world.
Eventually, the issue was solved after a series of patches and gameplay tweaks corrected the problem, following weeks of mayhem and discontent.