This book constitutes the refereed proceedings of the 6th Joint International Conference on Serious Games, JCSG 2020, held in Stoke-on-Trent, UK, in November 2020.<br> The 19 full papers presented together with 3 short papers were carefully reviewed and selected from 38 submissions. The papers offer a wide range in the use of serious games in several fields like learning, simulation, training, health, well-being, management, assessment or marketing and much more.&nbsp;&nbsp;