A modular helmet system with a removable/detachable/interchangeable exterior shell, an inner force-absorbing layer releasably connected to the rigid exterior shell layer, and a multiple fastening devices associated with the shell which allow the shell to be interchanged/replaced/reconfigured at will. The shell as a single piece unit, or combinable components bear the fastening devices designed to enable rapid, secure interchange of the helmet system's layers, therefore allowing the helmet to be adapted for climatic, functional, and aesthetic preferences.