The book "Metaverse, Digital Game Psychology", which TC Istanbul Kültür University Faculty of Science and Letters, Department of Psychology Res. Assist. Muratcan Keskiner contributed with the book chapter titled "Multiplayer Games vs Single Player Games: The Effect of Psychology on Game Choices" and edited by Prof. Dr. Nevzat Tarhan and Assoc. Prof. Aylin Tutgun Ünal, was published by Der Publishing.