This paper addresses the problem of the dependence of radiation damage in metals on the type and energy of the incident particle. The calculation and use of displacement and point defect production as energy dependent measures of exposure are described. A brief review is given of the quasiempirical, energy dependent damage function approach to determining the damaging effectiveness of different neutron spectra; included is a summary of derived effective damage functions and their dependence on or contribution to an understanding of damage mechanisms. Lastly, swelling rates of Type 316 stainless steel irradiated by neutrons, nickel ions, protons, and electrons are shown to correlate qualitatively with mobile vacancy production rates as deduced from computer modeling.