When a raid boss in an MMORPG (such as World of Warcraft or EverQuest) has an ability that reduces the tank's aggro by a fixed percentage. Since a tank can only build up a certain amount of aggro in a fixed period of time, and since the boss performs this aggro-reducing ability periodically, there will be a maximum amount of aggro a tank can produce.

In WoW, this first appears on Broodlord Lashlayer in Blackwing Lair, since previous aggro-reducing bosses reduce a fixed amount of aggro, rather than a percentage. It also appears on the three drakes, Firemaw, Ebonroc, and Flamegor.

Other players (besides the tank) must be careful to control their aggro on aggro ceiling fights so as not to pull aggro, since they are not being hit with the aggro-reducing ability.

A legendary Rogue on the Mug'thol server of World of Warcraft. Widely known for his incredible damage potential and 1337 skills in both PvP and PvE. He is the only known Rogue in the world to have tanked the Broodlord Lashlayer and General Drakkisath. The great black dragon Nefarian met his doom when he foolishly attempted to solo Miramar during the invasion of Blackwing Lair.