Instance Running 101 Explored Part 6

Pulling means mobs come to you.

This is a good opportunity to discuss aggro mechanics.

Firstly, a list of terms:
Mob - a non-player-character enemy. A kobold, or hellboar, or instance boss and so on.
Aggro - When a player has aggro, it means he is the primary target of the Mob, ie is the target that the mob will be attacking.
Threat - Described in more detail below, but basically the numerical value on the threat table.

Each mob has a little list (Referred to as the aggro table, normally) assigned to them. The list is filled with potential targets... the moment someone damages the mob, or heals/buffs someone already on the table, they get added to the table. The person at the top of the list is the person that the mob attacks.

Your position on the table is dependent on the amount of threat you have with that mob. Each point of damage you do to a mob is equal to one point of threat. Each point of healing you do to someone on the table is equal to half a point of threat. Buffs (that are applied during combat) have their own threat value, and so on.

Now, the system is tweaked slightly by giving the main target a bit of a buffer. If the tank has aggro, and one of the DPS's threat value climbs just above that of the tank, there won't be an aggro switch. If the DPS is at melee rage to the mob, he will need 10% more threat than the tank to be switched to as the main target (so, if the tank has 100 threat, the DPS will need 110 threat to get aggro). If the DPS (or healer) is at range, he will need 30% more.

Abilities like the priests 'Fade' temporarily remove you from the table. The threat value is still there, and any actions (eg healing) done during the time are still added to your total, the mob just simply won't attack you. Leaving the faded state will put you back in the relative position on the table, including right at the top if nobody has managed to surpass your threat value in that time. Shadowmeld works the same way.

Aggro dumps like Cower and Feint reduce the total amoutn of threat. Misdirection means that the threat the hunter generates for three shots is assigned to the target's total (hopefully the tank) instead.

Adding to the complexity are mobs (usually bosses) that have some kind of aggro switch or dump ability. Sometimes they will stun the person at the top of the list and then switch to the next person down, or go into a new phase of combat that completely clears the aggro table and starts again.
A classic example is the fight at the end of Ramparts. Once one kills the dragon rider, the dragon joins the battle... while it's the same fight, the dragon enters with a completely clean aggro table, automatically pre-aggroed on the tank (in other words, even though no damage has happened, the mechanics of the fight means that the dragon is aware of the tank, and has the tank on the aggro table). If, at that point, a heal over time ticks on the tank, the healer jumps to the top of the table, since the tank will have very little aggro.

Another quirk, already mentioned but worth mentioning again, is the mechanic behind the 'Taunt' ability ('Growl', for druid tanks). This ability increases the Tank's threat value to equal that of the person at the top of the table, and switches the mob's main target to the tank. If the tank is already at the top, it has no effect.

Whew, a long post today. Till next time...