Localization of deformation before large failure events is expected theoretically and observed in recent laboratory experiments and crustal data. Laboratory experiments reveal the localization of acoustic emissions, coalescence of fractures, and clustering of shear and dilatational strain before macroscopic failure. Geophysical observations show the progressive localization of seismicity and increasing clustering of events before several M > 7 events. Some frameworks, including bifurcation theory and viscoelastic damage rheology, analyze the processes leading to localization. Improved understanding of evolving localization may enable recognizing approaching large failure events in the crust and other systems. We encourage contributions that quantify the localization of deformation, including fractures, faults, acoustic emissions, strain components, seismicity, and geodetic data in numerical simulations, laboratory experiments, and the crust. Students and early career scientists are especially invited to participate.