Collective eXplainable AI: Explaining Cooperative Strategies and Agent Contribution in Multiagent Reinforcement Learning With Shapley Values ©SHUTTERSTOCK.COM/VLADGRIN Alexandre Heuillet Université Paris-Saclay, FRANCE Digital Object Identifier 10.1109/MCI.2021.3129959 Date of current version: 12 January 2022 1556-603X/22©2022IEEE Fabien Couthouis Ubisoft, FRANCE Natalia Díaz-Rodríguez University of Granada, SPAIN Corresponding author: A. Heuillet (e-mail: alexandre.heuillet@universite-paris-saclay.fr). Alexandre Heuillet and Fabien Couthouis contributed equally to this work. FEBRUARY 2022 | IEEE COMPUTATIONAL INTELLIGENCE MAGAZINE 59http://www.SHUTTERSTOCK.COM/VLADGRIN