This talk introduces Concordia, a multi-actor generative agent based modelling system. Concrodia’s design is drawing inspiration from tabletop role-playing games (TTRPGs) and modern game engines. The core of this framework is the Entity-Component architectural pattern, which enforces a crucial separation between engineering (reusable components) and design (hierarchical composition and configuration). This separation enables rapid iteration and high modularity, ensuring system robustness. The approach supports diverse user motivations, allowing for tailored scenario configuration to align with specific goals. We will talk about various possible applications of generative agent based modelling like creating synthetic users, in silico social psychology experiments, forecasting and so on.