This publication introduces the newly developed, integrated discipline of fracture and in-situ stress characterization of hydrocarbon reservoirs, through 16 well-illustrated case studies. These cover a wide range of tools, from borehole scale (logs and core) to reservoir scale (e.g. 3-D and 4-D seismic). It also covers surface studies (outcrop and remote sensing). In addition, it addresses the impact of fractures and in-situ stresses on fluid flows and their simulation.