NPC may refer to any of the following:
1. Short for Non-Player Character, a NPC or vendor is a character or monster who is played by the computer and not a real person. A NPC helps add life to a game by creating artificial players, each with their own abilities or personalities. If you're playing an online game and encounter another character controlled by a human, that type of character is referred to as a PC.
2. NPC is an abbreviation that may be used for non-printing character.
3. NPC is another name for NP-Complete.