In this paper we define a Multiple Agent System able to simulate an artificial society to be paired with a normative background. The purpose of this architecture shall be the simulation of a law to devise its impact. We analise some existent architecture (GAMA) that has already been used for simulating MAS, with BDI agents. In fact, GAMA technology is insufficient to guarantee certain validity properties and actual computational effectiveness that could instead be provided if we manage the rule system to interpret Defeasible Deontic Logic, a logic framework that satisfies the aforementioned properties. As a first step of an experimental endeavour aiming at law simulation by design, we provide here a theoretical model of the MAS which simulates the society.