Non-Player Character

Not to be confused with computer-controlled PCs and NPCs encountered in .hack media.

A Non-Player Character (NPC) is a character in The World who is not controlled by a human player. These characters are operated by the game's programming. NPCs include unfriendly creatures such as Monsters, as well as friendly creatures like Grunties, as well as the Shopkeepers and occasionally characters involved in The World's official events.
Vagrant AI could also technically be considered NPCs, since they are not controlled by a human at a Computer Terminal. However, as they are also not controlled by normal programming due to the unusual circumstances of their existence, they are classified as a distinct type of entity from regular NPCs.