The Warhammer 40K Core Rule Book 9th Edition Indominus Crusade is a hardcover book published by Games Workshop for the Warhammer 40K game. It contains the core rules for the game, as well as information on multiple armies and chapters/regiments that can be used in gameplay. This book is essential for players looking to engage in strategic battles in the Warhammer 40K universe, providing in-depth details on various aspects of the game. With its robust content and high-quality production, this rule book is a must-have for any Warhammer 40K enthusiast.