Mob (computer gaming)
A mob is a non-player character (NPC) or monster in a computer role-playing game (especially MUDs and MMORPGs). It is widely accepted as being short for mobile object or simply mobile, stemming from its use in the earliest text-based MUDs, and is commonly written either mob or MOB (the latter more often considered an acronym of Movable Object Block, a term for any on-screen moving object, or sprite). There appears to be some debate on the exact origins or the term, and backronyms such as "monster or beast" and "mere ordinary beast" have been developed.
Killing mobs can give such rewards as experience points and items. Usually the combat is player initiated, however, if the mob is "aggravated" or has aggro, it is configured so that it will challenge a player who enters within a certain range. This area is known as the aggro range. Combat between players and mobs is called player versus monster (PvM) or in a broader sense, player versus environment (PvE); as opposed to player versus player (PvP) battles where the emphasis is on defeating an opposing player rather fighting against the game system.
Usage in MUDs
As the term originated from MUDs, its use in those games has not changed much. Mobile is often preferred to mob.
The original term Mobile was originally coined by Richard Bartle in a paper describing an early MUD which was being constructed as a research project at the University of Essex. Although it originally referred to an object that could move (as opposed to one that couldn't), one reviewer of the paper misunderstood the term to be a reference to the classic children's toy or sculpture that goes by the same name - and referred to it as "an incredibly beautiful analogy to those hanging toys, which appear to move around randomly as if alive, while in fact being composed of mechanical parts and operating in accordance with fixed scientific laws". (Bartle was also suitably impressed by the analogy.)
Usage in MMORPGs
Mobs in MMORPGs usually refer to the generic monstrous NPCs that the player is expected to hunt and kill rather than NPCs that engage in dialog or sell items. Named mobs, also known as "elites", are special rarer monsters that are tougher and have better loot, usually distinguished by having a proper name rather than the generic "a goblin".