This book constitutes the refereed post-conference proceedings the 12th EAI International Conference on ArtsIT, Interactivity and Game Creation, ArtsIT 2023 which was held in São Paulo, Brazil, in November 27-29, 2023. The 40 revised full papers and 1 Short paper presented were carefully selected from 103 submissions. The papers are thematically arranged in the following sections: Part I: exploring new frontiers in music therapy; network dance and technology; computational art and the creative process; alternative realities, immersion experiences, and arts-based research. Part II: alternative realities, immersion experiences, and arts-based research; games; interactive technologies, multimedia, and musical art; human at centre.