In rock engineering and rock mechanics, a lot of observations and test are needed to determine the rock mass characteristics and the limitations of its usability at a particular location for a particular constructional work. Strenght as one of the basic mechanical properties of the rock mass is the most important starting point for the investigation of the breakdown that will occur if the stress within the rock mass exceeds its strenght. In this paper, therefore, emphasis is primarily on the conditions in which the breakdown occurs. Four basic mechanisms of breakdown in rock masses were analyzed: plane, wedge, rotational and toppling failure. By summarizing each of these types, it was found that their parameters required testing in the laboratory or in the field. There are described the ways of breakdown by shear, compression and tensile breakdown that we can interpret in certain experiments mentioned in the paper. The overall aim of the paper is to deal with the problem of knowing the rock mass behavior criteria, and the mechanisms that arise as a result of the collapse.