The black dots in these two shots represent the range a building has. Unlike most games, in Retro-Pixel Castles the range takes into account the actual walking distance from the main building, that way your villagers don't go wandering off on a grand adventure around a mountain to work. They will only work in areas they can reasonable reach from the building. The range is also adjustable by the player, if a player wants to restrict the work area to keep their villagers closer and safer with shorter trips they can pull back the range. If they want to take more risks and potential hits to productivity speed they can crank the range all the way up and grab resources normally out of reach. I have a lot of plans for building workload management, unlike the standard "Send the worker, collect resource, bring resource back" mechanics you see commonly RPC will have a slightly more complicated system, that will be mostly automated anyway. But I'll share those details when I get to them! In the mean time, enjoy these two rough shots of the buildings, workers and the building-range markers.
Shot one just shows a bunch of villagers working within range of their Lumber Mill, where as shot two shows the range, by actual walking distance and how in situations like this example your villager wouldn't attempt to walk all the way around the tree wall and collect resources on the other end.