This chapter provides an introduction to the field of Games User Research (GUR) and to the present book. GUR is an interdisciplinary field of practice and research concerned with ensuring the optimal quality of usability and user experience in digital games. GUR inevitably involves any aspect of a video game that players interface with, directly or indirectly. This book aims to provide the foundational, accessible, go-to resource for people interested in GUR. It is a community-driven effort—it is written by passionate professionals and researchers in the GUR community as a handbook and guide for everyone interested in user research and games. We aim to provide the most comprehensive overview from an applied perspective, for a person new to GUR, but which is also useful for experienced user researchers.