<p>This study examines the strain energy principle to address complex challenges in rock mechanics. Compared to conventional stress–strain assessments, the strain energy approach offers a more comprehensive perspective, representing a significant innovation in rock mechanics. The strain energy approach enhances reliability by considering energy accumulation and release alongside traditional strength analysis. Experimental studies indicate that the maximum energy stored and released during rock joint failure is comparable to earthquake energy capacities. This perspective introduces a novel approach for assessing rock mass stability during seismic events. The effectiveness of the energy-based approach is assessed using the hysteresis curves of rock joints under seismic loads. Experimental data reveal that the surface roughness of rock joints significantly influences the variation in strain energy with increasing normal stress. Moreover, evaluating the cyclic nature of earthquakes is essential for measuring strain energy, as the release of kinetic energy during an earthquake is inherently tied to its cyclic behavior. In this context, earthquake energy capacity is determined by analyzing the acceleration–time history of significant seismic events. Given that the strain energy from rock joint failure produces results comparable to earthquake energy capacities, the strain energy principle offers a more practical and realistic approach for assessing rock mass stability during earthquakes.</p>