How to Stop Mobs From Spawning Inside Your Base

The Right Modules for the Job

Spawning is controlled by modules, not by the field shape alone. Insert an Anti-Spawn Module into your Force Field Projector or Interdiction Matrix to prevent natural mob spawning inside the protected volume. Combine it with Anti-Hostile Module if you only want to block hostile mobs, or Anti-Friendly Module to keep passive mobs out. Anti-Personnel Module targets players instead.

Covering the Whole Volume

A spawn-blocking field only works inside the volume it encloses. If your base is irregular, either use Custom Mode to trace the shape or place multiple projectors on the same frequency so their fields merge. Field Fusion Module lets adjacent projectors combine into one continuous field, which avoids gaps at the seams where mobs could otherwise spawn.

Verifying It Works

After activating the field, stand inside at night and watch for spawns. If mobs still appear, check that the module is actually inserted (modules can be removed by shift-clicking) and that the projector has enough Fortron to stay active — an unpowered projector drops its field instantly. For persistent problems, add a Block Access Module to stop mobs walking in through doorways, and consider an Interdiction Matrix covering the same area for a second layer of defence.