As existing legal systems expand and become more complex, the search of effective ways to model them becomes increasingly important in the area of Computational Law. We chose normative multiagent systems (NMAS) to study the interaction between a legal framework, a set of agents and the fundamental theories that regulate the legal dynamics of a society. Using this approach in conjunction with Computational Tree Logic (CTL), we determined that there is an increasing possibility of encountering contradictions inside complex legal systems, which in turn could undermine their purposes. We consider that contradictions are the fundamental units to take into account when diagnosing a legal system, and we classify them into several kinds according to the system structure they affect. Finally, we point to the direction of research needed for the development of intelligent agents capable of targeting contradictions. © 2019 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of the scientific committee of the 13th International Symposium “Intelligent Systems” (INTELS'18).