The methodological foundation and methods for risk reduction have been developed in all countries of the world in the framework of the analysis of natural and technogenic risks. The problem was also intensively addressed to in Russia during the realization of the State Scientific Program “Safety of People and National Economy Assets in view of Risks of Accidents and Catastrophes” (1990-2000) and the Federal Research Program “Reduction of Risks and Mitigation of Consequences of Natural and Technogenic Emergencies in the RF until 2010.” In 1990-s it was suggested that the human factor be incorporated into the system of risk assessment in connection with unauthorized and erroneous actions. In the beginning of the 21^st century that approach proved to be insufficient taking into account the acts of local, national and international terrorism. The generalization of terrorism evaluations led us to the concept of three kinds of terrorism – traditional, technological and intelligent ones. They differ in damage factors and in their initial, secondary and cascade effects as well. In view of the above it becomes possible to improve the evaluations of terrorist actions and to incorporate the results of the study into the complex system of safety research.