Threat

Threat (also known as "aggro", short for aggression) is the value that describes how dangerous you are to a creature or Mob. Attacking a mob will generate threat, as will healing an ally who is being attacked by a mob (twice the value of healing up to full morale, one time for over-healing). Tanks want to generate lots of threat to prevent mobs from attacking other characters that might not be able to survive the attack. Non-tank classes want to reduce the amount of threat they generate as they damage the mobs or heal their allies.

Threat should not be confused with a taunt. A taunt is a debuff used by tank traited lines which forces a mob to attack the user, provides threat, and copies a multiple of the highest aggro that mob had that was not from the tank. This is good for tanks to grab mobs in the area or immediately pull mobs off others. This allows the tank to put themselves highest on the threat table if there was prior aggro to copy. (Note: using taunts before a fight has begun copies no threat, it only provides the amount bestowed by the skill.)

By traiting lines that are typically used for tanking (Guardian blue and yellow, Captain yellow, Champion blue and Warden blue), your threat will generate with a ratio of 3:1 from damage, instead of 1:1.