Hate

Hate is the calculation of how much damage you've dealt to an NPC. The player having dealt the most damage to that NPC will be the target of his attacks and spells. At first, the NPC attacks are directed to the first one he saw, but as soon as he has been dealt damage by a player, he redirect his attack to the one at the top of his hate list.

Each NPC has its own hate list of each known enemy, paired with the degree to which it hates that character. The list is constantly sorted by hate, and whoever is at the top of the list is chased and attacked. Any character who drops below 1 HP is removed from the list.

Managing hate
When two players are attacking the same NPC, the one dealing the most damage will be the target of its attacks. However, the character dealing more damage is not always the one which would be best fit to withstand these attacks. The most obvious way to manage the monster's hate is obviously to stop swinging at him. However, there are other ways that have been implemented to manage it. The exact way those factors stack together is not known, although it is apparent they stack somehow (either additively or multiplicatively).

Enhancements
A few enhancements have been introduced to either increase the hate you do per damage dealt or to reduce the hate perdamage dealt. Characters that are better suited to withstand attacks and/or spells may be attracted to those which increase the hate. Characters less suited for it, mostly for low hit points or low Armor Class reasons, may be attracted to those which reduces hate.

Increases hate

 * Warforged enhancements: Brute Fighting - Increases hate by 10 to 25% per melee hit, when active.
 * Paladin enhancements: Divine Righteousness - Increases hate by 100% per hit, temporarily.

Reduces hate

 * Rogue enhancements: Subtle Backstabbing - Reduces hate by 10 to 40% per melee hit, when active.
 * Wizard and Sorcerer enhancements: Subtle Spellcasting - Reduce hate by 10 to 40%.

Equipment

 * Attacks from the Treason weapon do 20% less hate.
 * Attacks from the Maul of Malice weapon do 20% more hate.
 * Wearing the Wretched Twilight reduces hate from spells and ranged attacks by 15%.

Skills
In addition, two Charisma-based skills can temporarily override the hate sorting:


 * A successful Intimidate check on a monster will bring you to the top of the hate list for 6 seconds.
 * A successful Diplomacy check will bring you to the bottom of the hate list for 6 seconds.

Special cases
Although most monsters use the hate system as described, there are some exceptions:


 * The Warforged Titan's aggro is either partly or completely randomized.
 * Stormreaver clears his hate list each time he casts Reverse Gravity.
 * Flesh Golems largely randomize their hate list and do not consider the damage dealt; they simply attack anyone in sight and change the target very often.
 * Rust monsters prefer to attack warforged.
 * Maruts have special hate for level 20 rogues with the capstone