How to display selectable unique zone/area/district in a game

Hi. I’m hoping to get direction on how to proceed with this desired goal (photoshopped image).


  • Define the zones (don’t need to change zone’s layout at runtime),
  • Ability to select/click on these zones (needs unique ids).
  • Should be customizable graphics, for examples show borders only, fill color, add stripes, and what not.

Where should I start? How can I define the areas in world space, what should I use to do that? Generate/procedural, meshes, landscape, decals, theories, keywords, keywords? I would appreciate any kind of hints or suggestions, I’m not looking for a full implementation, just how to go on about it. Preferably scalable method (+30 zones).

Some example games that have selectable zones: