Darken, C. and Kelly, J. "Individualized NPC Attitudes with Social Networks", Game AI Programming Wisdom 4, Charles River, S. Rabin editor, 2008.

This article introduces a method for largely automating NPC changes in attitude due to a player action. The method resolves the conflicting loyalties of the NPC’s to produce a single number per NPC that can be used to update the NPC’s feelings toward the player and drive future player-NPC interactions. The mechanics of the method are based on a constrained linear system, so it is computationally efficient, requiring only a single matrix multiplication in many applications.