Weak rocks encountered in open pit mines cover a wide variety of materials, with properties ranging between soil and rock. As such, they can provide a significant challenge for the slope designer. For these materials, the mass strength can be the primary control in the design of the pit slopes, although structures can also play an important role. Because of the typically weak nature of the materials, groundwater and surface water can also have a controlling influence on stability. Compiled and written by industry experts and containing significant case histories, Guidelines for Open Pit Slope Design in Weak Rocks follows the general cycle of the slope design process for open pits, from first steps such as field data collection and aspects of determining the strength of weak rocks, to an examination of weak rock types, and finally design implementation and operational considerations. It summarises the current state of practice for the design, implementation, and assessment of slopes in open pits, with a view to meeting the requirements of safety, as well as the recovery of anticipated ore reserves. Guidelines for Open Pit Slope Design in Weak Rocks is a companion to Guidelines for Open Pit Slope Design (2009), which dealt primarily with strong rocks. It provides guidance to practitioners involved in the design and implementation of open pit slopes, particularly geotechnical engineers, mining engineers, geologists, and other personnel working at operating mines.