This book explores video game design principles and practices through a grounded theory-based investigation of game designers’ accounts of their professional experiences. Drawing on qualitative data collected through semi-structured interviews with national and international game designers, this book seeks to build a comprehensive understanding of designers’ visions, core values, design thinking and methods, and operational frameworks related to video game development. As the dynamics through which theoretical frameworks and professional practices reciprocally influence one another in this field remain largely unexplored from a scientific perspective, this book aims bridges that research gap by presenting bottom-up insights into the attitudes, approaches, and shared understandings of game designers. Structured as a series of interconnected chapters, each with a thematic focus, this book examines key dimensions such as the implicit and explicit design processes followed by professionals, the conceptualization of video games as a medium for artistic expression, the dynamic tension between ethical responsibilities and critical issues, and the challenges of addressing accessibility and inclusion in design decision-making. Each chapter provides an in-depth analysis of its central theme while contributing to the reconstruction of a broader framework for theorizing video game design. This book is for scholars, educators, and professionals engaged in video game design, design studies, HCI, and digital media at any stage of their careers and with any level of experience. By grounding its findings in real-world practices, it presents an evidence-based framework that can inform future academic inquiry, curriculum development, and professional practice.