Abstract Reservoir compaction in depleting gas fields can cause seismicity, as has been observed in a dozen countries (Foulger et al., 2019). So, it is no surprise that some of the Dutch gas fields induce many earthquakes up to magnitude 3.5. Remarkably, the occurrence of Dutch seismicity is strongly clustered in two regions, while most fields induce no recorded seismicity at all. It has been attempted to explain this from differences in reservoir characteristics, but as yet, no reservoir property has been found that can explain the difference in seismicity. A new mechanism is proposed that can explain the regional variation of seismicity. For a few gas reservoirs, the evolution of potential fault slippage is simulated using the commonly adopted Mohr-Coulomb failure criterion. This shows that fault criticality is expected for reservoirs that showed seismic as well as non-seismic behavior. Apparently, some characteristic property is missing to explain the difference in behavior. Using published pressure histories for seismically active gas fields, the relation is shown between seismic magnitude and relative depletion. It appears that in many cases, the first induced earthquake is relatively strong which suggests substantial cohesion of the faults. It is plausible from the geological history that in non-seismic regions, fault cohesion is larger, so that slippage is inhibited.