NPCs function in the same manner as players in some aspects; completely different in others.
NPCs also have stats, although which and how they work is generally unknown. A few are either obvious or well-known.
- Hitpoints: Monsters obviously have hitpoints. NPCs can be healed.
- Mana: NPCs spend mana when they cast regular spells that belong to their class. For example, a Wizard NPC spends mana casting nukes, and will run out of mana if it casts enough. However, the vast majority of modern named NPCs have special abilities that do not consume mana, in order to prevent mana draining and other tricks to halt them. On regular NPCs, mana can be drained to prevent them from casting spells. A famous example are Cleric-class monsters, such as Lady Vox, who cast healing spells on themselves until they're out of mana.
- Regeneration: NPCs regenerate hitpoints, at a varying pace. Monsters that leave combat (for example, if the player dies) usually return to full HP very quickly, as an anti-zerg mechanic. NPCs also regenerate mana, slowly.
- AC: An NPC's AC is weighed against the player's weapon skill and ATK rating when being attacked in melee.
- ATK: When attacking a player in melee, the NPCs ATK is weighed against the player's AC when they hit. It is assumed that mobs have defensive and offensive skills equal to maximum for their level.
- Main Stats: NPCs probably have main stats (STR, STA, etc.), as spells exist that decrease these. It is unlikely that they function in the same manner on players, though.
- Resistances: NPCs have resistances that are checked when you cast spells. Some NPCs are extremely resistant, some only against certain schools. Many old bosses were 100% resistant to magic-based spells in order to prevent players from casting powerful spells such as Fear or Snare on them, but modern bosses are simply immune to certain detrimental effects, yet can still be hit with magic-based damage spells.
- Haste: An NPC with a Haste buff or wearing a Haste item will hit noticably faster. They can also be slowed.
The reaction radius, mostly referred to as aggro range by players, is the range within which agressive monsters will automatically engage and attack players. Only monsters that 'con' threateningly or scowling will engage a player. The reaction radius of monsters appears to be fixed per zone, and varies wildly. An example of a zone where monsters have a huge reaction radius is the old Plane of Fear, where monsters will engage players from very far away. An example of the opposite is The Lair of the Splitpaw (Infected Paw), where monsters have an extraordinarily low reaction radius.
The reaction radius of a monster can reduced with 'Lull' type spells, such as Lull, which lowers the reaction radius of monsters up to a certain level.
The frenzy radius, mostly referred to as assist range by players, is the range within which a monster that gets attacked will "shout for help", and attract the attention of its buddies. If you shoot an arrow at a monster that's standing right next to another on the same faction, the other one will come with it. If the monster's buddies are far enough away, they will not come.
The "shout for help" will not chain or jump, meaning that the buddy that came with the first one will not perform a new shout for help.
The frenzy radius of monsters varies.
The frenzy radius of a monster can reduced with 'Lull' type spells, such as Pacify, which lowers the frenzy radius of monsters up to a certain level.
Hate (or threat) is a number that indicates how much a player has hold of an NPC, which makes the NPC attack that particular player instead of others nearby. Hate is basically gained by doing damage and casting spells on the NPC, and various formulas exist that determine how much hate is gained for each attack or spell.
All NPCs keep a hate list, which is started every time the NPC enters combat, and reset when it leaves combat. Upon engaging an NPC, each player performing attacking the NPC, via melee or spells, will get on the NPCs hate list, and their rank on the list will constantly be updated depending on which player has performed the most "hateful" actions. If the number one player on the hate list dies, the NPC will begin attacking the second player, who will then become the number one target again.
Hate is of great concern to tanks and plays an important role of raiding, where players gang together to take down the toughest monsters.