It is a great pleasure for us to introduce this issue of the IJSG, which is dedicated to the Games and Learning Alliance Conference (GaLA Conf) that was held in Athens, November 27-29, 2019. Almost 70 participants converged in this beautiful, historic city in order to share knowledge and experiences related to serious games and gamification, their techniques and their application. A number of the best conference papers were selected, and the authors were invited to extend their paper with at least one-third new content, and to submit their paper to IJSG for a regular peer-review process. This issue contains three of the resulting articles, which gives an overview of the rich field of serious games.N/