This textbook introduces rock mechanics fundamentals in a simple way with a strong practical bias, assuming no prior knowledge in the subject. It is essential for students at graduate level who are facing careers as professional geotechnical engineers. The textbook is also suitable for undergraduates and engineering professionals in civil, mining, petroleum, and geological engineering. This new edition brings in a completely new chapter on tunnelling as well as more on numerical analysis and software, and sections on slope failure mechanisms and petroleum geology.