This book explains the foundational practices of the Great Perfection (Dzogchen), widely considered to contain Tibetan Buddhism's most powerful methods for transforming the mind. Traditionally, this book was used as an instruction manual for those engaged in long-term meditation retreat. The practices contained in Great Perfection are commonly referred to as the preliminary practices (ngondro), and are considered essential for the correct practice of the Great Perfection, as they ensure the practitioner has a solid grounding in the fundamentals of the Buddhist tradition. In addition, this book contains an historical overview of the teachings, a section on the importance and meaning of empowerment, and extensive material on how to properly receive and study the Dzogchen teachings.