Invisible void zones
Invisible void zones refers to a phenomenon observed during the Four Horsemen encounter in Naxxramas. Due to what is believed to be a flaw in the game's graphics rendering engine, Void Zones cast by Lady Blameaux would occasionally fail to render on a player's screen. As Void Zones were summoned on top of a player within 40 yards of Lady Blameaux, and dealt approximately 4000 damage per tick, such an occurrence would almost inevitably lead to a wipe as either a Blameaux tank or his healer would perish.
Legacy
For a player that has never experienced them, the claim of "invisible void zones" may sound like a pathetic excuse made up to cover for a player simply being inattentive during the fight. As death-by-Void-Zone was almost always followed by a wipe, there is always immense pressure to skirt the blame. Unfortunately, invisible Void Zones were a real phenomenon.
It is worth noting that the advent of BigWigs, and a timer for Void Zone casts, made dodging all Void Zones -- invisible or otherwise -- a much less daunting task.
Also, to be fair, there are far dumber ways to wipe to the encounter.
