The NPCs can buy and sell stuff, you could sell them the Technology including Blueprints etc. They will improve themselves too alongside you, and roughly match your own tech level, or at least a more “balanced” version of it (as in spread evenly over all tech branches) in case of min-maxing players who develop one tech extremely high while disregarding other tech, making it possible for players to have better tech than NPCs without NPCs being stuck at the Stone Age.
Yes they will use the same Recipes as Players. And I haven’t seen Games where the AI actually wastes Resources, except when attacking the player over and over without realizing their armies always die.
What I always saw was the AI having shitloads of Resources and not fucking using those Resources. Or even worse, the AI not being written to work with limited Resources and then running itself into starvation.
One thing for the “Medieval Period” and earlier is the fact that almost everything can be made out of Wood and Stone. Wood is renewable and Stone is everywhere. Food and Water can easily be solved by making sure that the Villages are next to a River, Lake, natural Spring, Aqueduct or simply have a Water Well.
The NPCs also have the advantage of multiple people working together, so they can split tasks way more easy than a singular Player ever could, which means less Automation required, and once they can make Machines, they will ofcourse use them to free up other places for their NPCs to work at.
NPCs will most likely start up with a Camp of a few Tents or small Huts around a “Religious” Altar or Shrine. They will start cutting Wood and making Fields where it is logical, and then build actual Houses. Having the Village constantly run in the background can have performance Issues, but I will try to reduce them as much as possible, especially when there is multiple Villages.
And dont forget, Villages can easily just go and flatten the Landscape for more Building Area they have enough Slave Power, uhh I mean Manpower to just do that. I can also just start each newly generated Village with the Tech other Villages already have, just not in a written down State, because then you could just generate new Villages to steal Tech from, instead of stealing from the already developed Villages. Or I will do something else to prevent stealing Tech from newer Villages.
One thing about the Map, at least in the early stages of the Game Development, it will be of the “Islands in the Ocean” Type, because it should generate the Surface of one Island as a whole all at once, at least for things like Rivers it is needed in order to set the proper origin and flow direction. Vertical Chunks below the Surface wont generate unless needed (i.e. when you dig into them).
Another thing is that the Village will go with a Grid System, where the Grid is aligned to the Chunks, both horizontally and vertically. Now you may think that would look ugly as fuck in Minecraft, but dont forget each 16x16x16 Chunk in the Game has the Size of a 4x4x4 Block Cube in Minecraft, and a grid that small in Minecraft would actually look good again. The Reason for the Grid being so Chunk aligned is that I essentially just need to put an ID into each Chunk to declare which Part of what the Chunk is, like a Street or the Entrance Area of a House for example, perfect for Pathfinding.
The “Religious Places” will purely serve the purpose as a Respawn Point you can select just like how Minecraft Beds work without the Sleeping where the last Altar you prayed to is the one you will respawn at. I am thinking of naming the Hardcore Mode “Atheist Mode” where you just dont respawn. XD
There will also be other selectable Respawn Mechanics that I mentioned earlier, like you respawning as a different Member of your own Family, if you have one, kindof like at the end of Red Dead Redemption.
But the Religious place will exist even if its not available as Respawn Mechanic, because the NPCs believe in something. And it wont be any real life Religion, I will make one up myself, dont worry.