A NPC (Non-Player Character) is a character who is not created by the player. Any character who interacts with the PC (Player Character, created by the player) is a NPC, however the term is often used to describe a character who joins the main protagonist (the PC (Player Character)). In these cases, the NPC acts as a party member, and assists the PC in his or her quest with his or her skills. Sometimes, they are invaluable to the player. Some quests can only be completed with the assistance of specific NPCs.

In Baldur's Gate II, the party-joinable NPCs also interact with the PC, each other, and the non-joinable NPCs the party encounters.

See also the canon Baldur's Gate NPCs and Baldur's Gate II NPCs, as well as the BGII mod NPCs.