Create blocks devs can place in the world that will make all NPCs nearby avoid that block and surrounding area. Can be placed underground to avoid NPCs from falling off cliffs, into water, etc.

• Make the range configurable
• Allow an exclusion list so a specific NPC (or NPC preset) can go into that area.
• Allow a toggleable "is invisible", so it behaves like a barrier block. If the range is 1x1, players can copy/paste this block on top of towers, around cliffsides, on top of short walls, etc.