This book constitutes the refereed proceedings of the First IFIP TC 14 Joint International Conference on Entertainment Computing and Serious Games, ICEC-JCSG 2019, held in Arequipa, Peru, in November 2019. The 26 full papers, 5 short papers, and 16 poster, demonstration, and workshop papers presented were carefully reviewed and selected from 88 submissions. They cover a large range of topics at the multidisciplinary intersection of design, art, entertainment, interaction, computing, psychology, and numerous serious application domains. The papers are organized in the following topical sections: mixed reality; virtual reality; entertainment algorithms; game design and development; interaction technologies; measurement and effects; and serious game applications.