The book "Experimental Rock Deformation - The Brittle Field" offers a comprehensive examination of experimental rock deformation, particularly regarding the phenomena of brittle fracture. It makes a clear distinction between brittle and ductile behavior of rocks, which relates to the different mechanisms of fracture and flow. The final chapter addresses the transition zone between these two behaviors. This new edition takes into account developments from the last two and a half decades and is supported by a second author to expand the content. The focus is on the mechanical properties of rocks in the laboratory, adopting a materials science approach. The book excludes topics such as the role of joints and shock phenomena, which are significant in engineering and mining applications.