Non-Playable Character

Non-Playable Character or NPC for short, is a generic term that refers to entities in MMORPG that are not controlled by players.

Background
In YGGDRASIL NPCs exist within the game to provide support to the players. Their purpose was to deliver quests, act as support characters, etc. NPCs were programmed with limited artificial intelligence to interact with plaer. Within the game, these artificial intelligences only move according to their program. In other words, they were the same as moving mannequins, only acting on pre-programmed action.