How does AI choose where to place its cities?

[Bungus]

How does AI choose where to place its cities?

Having a hell of a time getting the AI to settle where I want you to in my Earth mod. So after redesigning the map, making it more compact, Consulting mineral deposit maps and atlases to ensure somewhat accurate resource placement, and then Distributing resources so so the proper civilizations have plenty potential for development, the goddamn Greeks only want to build is Siberia. Scandinavians loath building in Scandinavia. And the Dutch can't be deterred in their pursuit of founding their second city in Kazakhstan.

Couldn't find anything on the search function. I'm sure an in-depth analysis of ai city placement has been done here on the forums, help me find it. The only consistantly in regards to ai city building Ive seen is that they will pick the most ******** spot. I'll post some screens when I'm home but Greece for instance will ignore every resource in anatolia to found some far flung city in asia that provides them with nothing.

Whats happening under the hood?
Thanks

 

[Civinator]

Hi Bungus, I´m not aware of such an 'in-depth analysis of ai city placement'. Two observations about city placements: In C3C the AI never moved its settler from a starting location to another tile, when it can found a city in that tile and the second and much more important (and logical) is, that the AI will and can only settle in terrain, that allows the founding of a city. If you allow the founding of cities only for a certain terrain, you can direct the AI much better where it will settle down.

Since many years I´m experimenting about a method to force the AI not only to found cities in the correct location, but also with the correct names, using marsh terrain and resources for the city names. I made several posts about that method and especially told one civer in these forums how to do such a map. Unfortunately when he released that map by using the most simple parts of the ideas and methods I had explained to him, he gave all the credits how to do such a map to himself.

While working on my worldmap, it was found out, that the number of different strategic/lux resources in C3C is limited to 256 (contrary to older posts that this number would be unlimited) - too less for a world with 512 cities. At present I´m working on a worldmap starting in 1518 AD, allowing a number of preplaced cities and another number of tiles that are allowed to found a city, so I can fill the world with 512 cities with the correct names and the correct placements. It still can happen, that an AI civ like the Greeks in your example founds (or conquers) a city in Sebiria, but this city will have at least a somewhat correct location and the correct name. The No-Raze-Patch is needed for doing a map that way.

Yoda Power had another very good solution to that problem by using cleverly terrain that restricts the movement of wheeled units in his great 'Giant Earth' map. Early settlers cannot pass through that terrain, restricting the early expansion of civs to some limited regions.

 

[Bungus]

Gotcha. Takes marsh tiles out of the equation then, but works in many cases. Unfortunately thats whats Im looking for, no isolated greek cities in Kamchaka

I think its outside my scope to try to figure out how the ai ticks at this point in that regard. Theres definately no rationalizing it. Ai is like a stubborn 3 year old, like No, I want this one! Even when that one is a bowl of bleach

 

[Oni Ryuu]

Hi Bungus

I like your analogy.

No, I want this one! Even when that one is a bowl of bleach

I started work on a world map where you couldn’t produce settlers until after the late Bronze Age collapse. I was going to place tailored barbarian camps in my desired city locations. Each camp would include an immobilised settler, without population points as the only way to found new settlements.

You can’t guarantee ownership but you can control where each city is placed.

 

[Bungus]

Thats another way of doing it. Of course youd still get far flung cities as the ai's stacks of soldiers wander and fight barbs.

I was contimplating the feasability of doing something like a 'paradrop' settler with 0 movement. That way it can only paradrop from the place its built some set distance. But do you need an airport flagged improvement to paradrop?



Easiest solution for me might be to just

 

[Bungus]

Tested it briefly. It works for us if you give the palace or other improv the vet air units and airtrade (maybe just vet air units tag does it). Unfortunately, ai does not seem to be airdropping them. they will still build two or three settlers, but they just sit. May try playing around with defense values (doubtful defense tag will do anything, as if its assigned defender it probably wont settler, but who knows. I have heard offense or defense units will bombard..) or anything else I can.

Shame cause it'll really be a nice way to enforce a spreading expansion. The setler "airport" can always be made to go obsolete by the middleages or whenever, long before flight units show up. (Hopefully airdrop feeds off vet air units tag and not air trade tag so as not to bog down processes and connect all your cities for resources and trade.) You could give the palace the ability or maybe theres a way for small wonders to build a ____ (Settler-port) in every city with Quint's hacked editor or something.
if the ai cann be convinced to use em

 

[Vuldacon]

Bungus... Yes you only need to flag "Veteran Air Units" to any improvement to allow Airdrop and Airlift of any unit that is set to Airdrop and or Airlift. .

I have used this for many years in EFZI.

Great Wonders, Not Small Wonders, can place Improvements in all cities when the Great Wonder is built. Those Improvements can be flagged to allow Airdrop and Airlift.
The AI will tend to build Great Wonders more when the game starts because they are not at war or not in strong battle.
You can have a Great Wonder place Improvements that require a Resource to build and the Improvement will be placed before having the Required Resource. That allows you to have the Improvement Auto-Produce a Unit later when you gain the needed. Until the Required resource is obtained, the Improvement will only allow all other settings flagged for it. This works very well and is advantageous and beneficial in controlling the AI and what you want to take place in Game.

 

[Bungus]

Gotcha. That could be a useful trick. An improvement with latent abilities. None of the hacked editors allow for a small wonder to "place x in all cities", though? Not huge, I guess 31 great wonders could be built each requiring one of 31 non tradable starting techs that put a "vet air units" improv in all cities, thus allowing the settler to settle-drop.

But this is all moot if I can't get the ai to use the damn things

 

[Bungus]

Btw, the palace cannot be flagged a grat wonder can it?
I tried and I got a crash," can't find pedia icons\ blablalba palace" or something. Guessing its a major conflict cause of cause theres one in every city

 

[Blue Monkey]

TAM (The Ancient Mediterranean) is a mod/scenario with civ specific wonders. You might look at the mechanics of how they did it, then apply that to your design. There are also scenarios (RAR iirc) that include buildings flagged in such a way that they can only be built in same city as the palace. This would allow you to establish the limitations you want for the wonders.

 

[Bungus]

Yeah but wr're talking about drapes when the foundation aint even set. I can't even get ai to drop cities with preplaced immobile settlers with (or probably without) the paradrop

 

[Vuldacon]

Bungus... Please set Up what I said and you will see that it works Great... Absolutely. There is NO "Drawing Board", it works.

 

[Bungus]

No, it doesnt. Ai wont airdrop a settler

 

[Vuldacon]

Bungus... I had forgotten it is Hard Codded that the AI does not Airdrop Settlers or Units with the Settler setting flagged but as a Human Player you can Airdrop settlers.

 

[Bungus]

Yeah, figured as much. Damn shame would have made for a good creeping expansion. Just ended up preplacing the first two citys (empty, 1 pop), and with a lot of tinkering the ai can be cajoled to stick to its backyard at game start. Maybe a Giza in Ghana or an Antioch in Indian but no Lyon in mongolia