Abstract <p>The authors analyze the main approaches to the assessment of the dynamic fracture tendency in rocks on a laboratory scale and report the data of experimental investigation of rock samples. It is shown that the dynamic fracture tendency of rocks depends on their loading conditions, namely, on the stiffness ratio of the loading system and loaded object, on the energy input rate (loading/deformation rate) and on the type of the stress state. It is found that the change in the loading parameters of rock samples during a lab experiment can influence their behavior in fracture; for this reason, in assessment of the dynamic fracture tendency in rocks, it is necessary to consider not a sample, individually, but the whole press–sample system.</p>