Threat

Threat, also called aggro, is a hidden counter that determines how likely a monster is to attack a given player.

In general, monsters attack the player who has currently dealt the most damage to it. Each player has a separate threat value for each monster they are fighting, which is calculated as a function of the total damage dealt by the player and whatever threat modifiers they used, such as Incite and Provoke, which adds 200,000 or 250,000 to the user's threat.