Understanding how faults accumulate and release stress through a spectrum of slip behaviors, from regular earthquakes and earthquake sequences to swarms, tremor, and slow-slip events, remains a central challenge in seismology and fault mechanics, with critical implications for understanding tectonic processes and seismic hazard. This session brings together studies investigating the physical mechanisms governing fault slip and earthquake source processes across a broad range of spatial and temporal scales and tectonic settings, including interplate and intraplate environments and anthropogenically induced seismicity. We welcome contributions spanning detailed investigations of individual seismic sequences and fault systems to global-scale analyses, using observational data, numerical modeling, laboratory experiments, and theoretical approaches. Studies addressing earthquake nucleation, rupture dynamics, fault interactions, stress evolution, frictional behavior, and the mechanisms underlying transient fault slip, including swarms, tremor, slow slip, and induced seismicity, are particularly encouraged. We also welcome studies that integrate multiple methodologies or leverage emerging technologies and novel datasets, including machine learning and artificial intelligence for seismic phase detection, catalog enhancement, event characterization, clustering, and forecasting. By bringing together perspectives across different modes of fault slip and methodological approaches, this session aims to advance our understanding of the physical processes governing fault behavior across timescales and contribute to improved assessment of seismic hazard and fault-system response.