The deformation energy budget describes how energy is stored and consumed within crustal systems. Energy stored as uplift against gravity, off-fault deformation and/or mineralogic changes can be released in the creation of new fractures, frictional heating along faults and/or radiated seismic energy. Innovative field measurements, numerical modeling and experimental approaches are providing new constraints on the energy budget within deforming crustal systems. The energy budget framework allows comparison of the energetic importance of diverse deformational processes operating in crustal systems. This framework enables tracking the evolution of the energy budget throughout time, and comparing energy budget partitioning in any tectonic system as individual fault segments propagate, interact and perhaps link. Moreover, the energy budget framework governs the rupture style and slip distribution during an individual earthquake, and is key in understanding multi-fault ruptures. Evidence suggests that new faults develop in order to optimize the overall efficiency of the system. Thus, constraining which processes dominate the budget in various tectonic systems and moments in time may help predict the timing and geometry of fault and rupture propagation and interaction. For this session, we encourage contributions that provide estimates of the evolving components of the energy budget using diverse methods, including numerical models, scaled physical analog experiments, deformation experiments on natural rock, and geophysical and field observations. Interdisciplinary work that combines several of these techniques are particularly encouraged.