Traditional methods of geotechnical engineering still dominate the approach of risk and reliability. Following the importance of understanding and asssessing geotechnical hazards, vulnerability and risk, new concepts and techniques of reliability analysis have been developed in the last 20 years. While these are widely accepted, application has been very slow. With a structured approach, this book introduces the reader to basic principles and methods of geotechnical risk and reliability and demonstrates their relevance for improved understanding, more effective strategies and better problem-solving skills. Reference is made throughout to the latest developments in the application to geotechnical problems. Attention is given to the ways in which reliability analysis and assessment of hazard and risk along with suitable observational approaches can facilitate the management of risk.