What determines border-expansion and tile prices?

[unundindur]

Do we know how border expansion is calculated?

I have long had a grime with the way border expansion seems to constantly take the worst possible tiles around my city. It doesnt take luxuries first, nor does it take natural wonders, and it doesnt seem to see where the good resources further away are. I originally thought the game only looked at food, and later on total number of resources on a tile, but was surprised to see it pick a stright plain over a plain with river for instance.

Yesterday I did a bit more research into the price of tiles and was surprised to see that two identical tiles (flooded planes, over river) had different costs. One cost 70, the other cost 140 even though both were 1 tile away from my capital and connected to two of my tiles.

If anyone can sheed some light into how the computer expands, and how the cold cost is calculated that would be very very useful to my Civ-group

 

[TheMarshmallowBear]

All I know the expansion of culture is more hard to go over difficult terrain other than easy, including rivers.

So it will pick an "easier" tile over more "difficult" one.

I think Tile cost also depends on what's on it. i.e if a hill, forest, or a river. I know mountains make it VERY expensive.

 

[Ranos]

Cultural expansion is based partly on a reality standpoint. Areas that would be "easier" for your citizens to get to are acquired first. So flat terrain and, if your city is on a river, the hexes that are on the same side of the river as the city. Land has a higher priority than sea. Luxuries and food have top priority.

I honestly don't know for sure how it's all figured.

For purchasing, it seems that tiles that are next in line for cultural acquisition and then the ones that will be selected after those are cheapest. The further away from cultural acquisition they are, the more they cost.

Just my observations.

 

[MilesGregarius]

...Land has a higher priority than sea...

I think food trumps this as I regularly watch my borders expand out to sea, and even ocean hexes, while much more desirable, but foodless, hexes don't even show pink borders when looked at on the "Buy a Tile" screen.

...For purchasing, it seems that tiles that are next in line for cultural acquisition and then the ones that will be selected after those are cheapest. The further away from cultural acquisition they are, the more they cost.

Type of terrain also factors, as anyone who has ever tried buying a mountain tile to start building Machu Pichu can attest.

 

[joncnunn]

There is a method to the cultural expansion madness, but you may need to play several games to see it.

Natural wonders have the impassible terrain triple Mountain cost, and most of them produce 0 food. Which places them towards the bottom of the cultural expansion list.

It is quite often the case that you'll be better off cash buying the tile.

Also, clearing marsh will do wonders in moving up the tile. And also flat grassland / plains with a forest can often be moved up the priority list by forest chopping, but be aware you'll get fewer hammers for chopping outside your borders.