Electropulse stimulation provides a means to fracture hard rocks into small fragments with the use of high-voltage electric pulses. As these techniques offer a frictionless method to break rock in tension, they have the potential to improve drilling, processing and excavation by reducing energy requirements and decreasing equipment wear. However, to date, descriptions of the processes involved in hard-rock electropulse stimulation remain largely empirical in nature - concentrating on the macroscopic effects of the electrical discharges, rather than their underlying causes. Results from a recent series of experimental studies and associated numerical models investigating the effects of electropulse stimulation on hard rock at the grain scale are outlined in this paper. The effects of the electric pulse treatments on the rock microstructure and the nature of the fragmented particles produced are also described. These results are compared with numerical simulations that track the path and effect of the voltage pulse on the rock mass. The implications of these results on the performance of electropulse methods are discussed for a range of operating conditions and rock-types.