Tobias Ahlbrecht & Jurgen Dix 
Multi-Agent Programming Contest 2021 
One-and-a-Half Decades of Exploring Multi-Agent Systems

This book constitutes the 15th edition of the annual Multi-Agent Programming Contest, MAPC 2020. It gives an overview of the competition, describes the current scenario. Furthermore, it summarises this year’s participants and their approaches and analyses some of the matches played and the contest as a whole. In the second part, each team contributed a paper describing their approach and experiences with creating a team of agents to participate in the contest.