In its simplest form, engineering geology is the application of geological concepts to civil or mining engineering projects. It takes relevant geological principles and scopes out the types of engineering issues that are likely to develop. The most important component of this field of endeavour is a comprehensive and unambiguous rock mass description for engineering purposes. The principal components of this are weathering, structure, colour, grain size, rock material strength and rock type, together with descriptions of natural discontinuities in terms of type, orientation, persistence, infilling, surface attributes, and water. In total, the descriptive process gives details of block size, block shape and the surface condition of rock mass, as well as the character of the intact rock material itself.

Engineering geology often forms the starting point for a rock engineering study. Once the rock mass has been properly described, attributes from a rock mechanics view point can be generated that will assist in the process of developing numerical models. For example, rock mass input parameters used in a mathematical analysis are normally generated from an engineer geological assessment of the rock mass.