This paper briefly describes the “Natural Slope Methodology-NSM”, developed by the late Colombo-Hungarian engineer Tomas Shuk E.. This methodology not only provides direct tools for geotechnical probabilistic slope stability, hazard and economic decision analyses, but it also furnishes a large geotechnical parameter data base with attractive cost and time effectiveness. This methodology obtains its results on the basis of two geometrical parameters (L = horizontal length and H = vertical height) of natural slopes (Shuk 1968, 1970, 1993, 1994b, 1999), which are measured for each slope on topographical maps of an appropriate scale. Underlying NSM is the basic premise that "nature is the best in-situ test", and NSM tries to become the best possible quantitative interpretation of the geomorphological results produced by nature's massive adaptation processes to climatic, seismic and other environmental conditions the best in-situ test”, of the result produced by nature’s massive adaptation process slopes