Abstract Fault damage zones dominate the mechanical, hydraulic and seismological properties of faults yet the relative contributions from processes leading to their development and growth is obscure. In this study, we investigate the damage development related to slip on rough faults and passage of earthquake ruptures. We compare the cumulative damage with slip and damage distribution from numerical models against field data from exhumed faults with slip less than 3.5 m within the Atacama Fault Zone in northern Chile. Models are constrained by experimentally determined mechanical properties of the host rock. We perform simulations of damage accumulation during quasistatic slip on rough faults and during sequences of earthquakes on planar and rough faults governed by rate and state friction laws. Both sets of simulations include Drucker–Prager rheology of the bulk to identify off-fault damage where the yield stress is exceeded. Our results indicate that the extent and distribution of damage depend on the characteristics of fault roughness, amount of slip, and, when present, the intensity and variability of dynamic ruptures. When typical values for fault roughness are used, the scaling of damage zone width versus slip during quasistatic slip is comparable to that observed in the field data. Earthquake rupture on smooth faults by itself does not explain the field data. Simulations of earthquake sequences on rough faults leads to significantly larger damage zone widths with slip than that observed in the field data, suggesting the development of damage for small displacement is dominated by quasistatic slip on rough faults.