Non-player characters (NPCs) are characters run by scripts or a DM. They are the people and creatures that populate a module and that player characters interact with. Their roles range from quest givers to generic extras; from merchants to adversaries; and so on.

Interaction with NPCs can take several forms. The official campaigns have pre-scripted dialogs that players initiate by clicking on (non-hostile) NPCs, as well as the occasional pre-scripted dialog initiated by the NPC itself. These dialogs often give the player a choice of responses, but the choices are limited to those written by BioWare (more generally, by the module's author). This approach was chosen to allow authors to weave a tighter, more gripping story. The game also includes support for keyword-based text parsing system, allowing builders to customize the way players interact with the game's world. (For example, some modules use the latter method when a password is required, but use the simpler pre-written approach for other situations.)

The game supports voiceovers for NPCs, meaning dialog can be heard as well as read. Voiceovers tend to be incomplete, though, even in the official campaigns; a dialog may start with NPC voiceovers, then shift to soundless. In particular, and of special note for the hearing-impaired, voiceovers are not essential for players; text always accompanies pre-recorded voice in an NPC dialog. (Given the flexibility of the game, it is possible to construct a custom module where this is not the case, but doing so is more time-consuming and rarely, if ever, done in practice.)

See also: Category: NPCs