In this paper we introduce a mathematical model of conflict that enhances Richardson’s model of Arms Race accounting for interactive scenarios, such as the ones provided by CRPGs (Computer Role Playing Games). Such an improvement translates the model into an HCP (Hybrid Control Process). We also provide a sneak peek at the multidisciplinary project Two Familes (A Tale of New Florence), set up to illustrate the applications of the model. Two Families will result in a Neverwinter Nights 2 module featuring non-linear interactive storytelling, and a substantially different user experience based on complex political interaction between in-game factions and the overall plot. Keywords Game Design, Interactive Storytelling, System Dynamics.