Social Modeling via Logic Programming in City of Gangsters

Abstract

City of Gangsters is a commercial strategy game with significant social modeling mechanics: it is a tycoon management game, where the player needs to work their social connections with a network of roughly 1200 NPCs to get things done, and NPC opinions about the player modulate the player's ability to succeed. We found logic programming to be well suited to our knowledge representation problem, including the need to perform inferences over a relationship network with more than a thousand active characters, and to provide the player with meaningful feedback about the consequences of their actions in the social space. In this paper we present the technical details of this social modeling problem, the details of our logic programming implementation, and how this interacts with the game's design and its social and material economies.