The main purpose of the non-player character is to help the virtual world run smoothly. The NPCs are like the characters in a novel. The purpose of each character is different and depends on the type of the novel. But the final purpose of the characters are to shape the novel in a smooth way.
The purpose of each NPC in a virtual world is different. A newbie guide will provide basic information to the new players and guide them through some newbie practices. For instance, a guard in front of the castle will stop the players from entering without meeting some requirements; a shopkeeper will provide some trading services to players; some other NPCs may be talkative and provide different background information of the virtual world. Every NPC has its own purpose and their final purpose is to make the players play in the virtual world smoothly.
In some online virtual world, NPC will act as player replacement. Sometimes players want to play in the virtual...