Starved-out cities

Michael Daumen · August 13, 2003, 16:19

OK, so when a size one city loses its food, it is converted into a lone settler. Does anyone know how close it needs to be to get picked up by another city's support?

Is it possible to make a map where any new city built will result in starvation automatically? I am thinking of combat engineer or legion units that could make fortifications (the starvation is to prevent cheating by players - I have no idea what the AI would do with a settler on such a map).

I suppose I could live with small camp-like cities but I dont want to

Boco · August 13, 2003, 16:46

If I understand you, closer to your city than to another civ's city. I don't know if there's a max or whether land mass number fits into the algorithm. I suspect not.

Can you afford to have only one or two terrains that produce food and place them only at city sites that you want? Their exact settings + irrigation would dictate max city size.

Terrains with 0 food and no irrigation bonus won't support a viable city. It starts as size 1, with a -1 food rating and no reserves.

If this is a viable suggestion, do I get to learn the topic?

:) Smiley · August 13, 2003, 17:29

Just make all terrain give no resources, then there'll be no incentive to make cities except for the stacking benefits, and even that's questionable as the city would be destroyed when the first unit loses.

yaroslav · August 13, 2003, 18:29

Give a setler to the AI and it will build cities

There are some things you can do:

A) Modify the terrain (time-costly)

B) Include up to 255 cities. If you don't want 255 cities, just add some barbarian cities non visible (you can create cities in weird places, like non-displayed coordinates that will be no visible, ask Henrik

). Problem: if a city is destroyed, an AI could build a new city.

C) Hex-edit the map and put a value of 0 in the field of 'fertility' in all the squares of the map. This is very time-costing and it has been not checked (IIRC) but it should work for you

Mercator · August 13, 2003, 18:47

I take it you want to prevent new cities being built?

I don't know about human players (I guess a "house rule" should be effective enough), but the AI can be manipulated easily enough.

Use MapCopy to change the fertility value of all squares on the map to zero.

The AI will only build cities on tiles with a fertility value of 8 or higher.

And, interestingly enough, the AI will always build a city if a tile has a fertility value of 15 (the maximum). This can be used to create AI cities by events. Edit a particular square to fertility value 15 first, create a settler on that square with an event and it will build a city there right away.

Manipulating the fertility values is perhaps the most sensible way to prevent the AI from building cities. On a standard map (i.e. without any fertility changes), the AI will build its cities only on the terrains in the Grassland and Plains slots, and regardless of what the rules.txt says.

Mercator · August 13, 2003, 18:48

cross-posted... But it has been checked, and isn't so time costly if you use MapCopy.

yaroslav · August 13, 2003, 19:05

Sorry Mercartor, I'm ashamed, I didn't know that it has been checked and I didn't know that MacCopy has these function

:shamed:

Mercator · August 13, 2003, 19:16

It can only set everything to zero though, not do any of the more fancy fertility things I was talking about.

Oh, and just in case anyone here wants to use mapcopy but is intimidated by its readme. Here's how you turn an entire map in a savegame infertile... type in the command (DOS) prompt:

Code:

mapcopy your_savegame.sav -f:ZERO

Boco · August 13, 2003, 19:50

Did I see a post about an updated tip article on hex-editing? "Hex-editing" for Idiots?

:) Smiley · August 13, 2003, 23:32

Can someone prime me on the details of how fertility works? What else goes into determining fertility values for a terrain square?

Mercator · August 14, 2003, 10:01

@Boco: Where?

@

: I'm not sure about the details myself. Fertility is stored as part of the map data in half a byte (4 bits).

Values range from 0 to 15, and the AI will only build cities on squares with fertility above 7 (8-15). Only grassland and plains will ever have values above 7.
Fertility is reduced to below 8 on city squares and squares adjacent to cities.

Other that that, I'm not sure. I think the values kind of depend on the size of the map, the total amount of land and the total amount of fertile land. So while a map may start with fairly high values, they will likely drop as more cities are built and the amount of available fertile land drops.
Apart from this, I think only rivers, resources, and possibly roads, irrigation and mining have some influence on fertility. But I'm pretty sure none of it has to do with the terrain values as in the rules.txt.

Gradually dropping fertility over time would also mean the map becomes less desirable for the AI. This might even be a fundamental part of curbing AI expansion, seeing as the AI immediately builds a city on fertility 15, but not on fertility 8. So presumably it prefers a higher value and isn't just content with anything over 7. Maybe it's even a simple probability function...
But this is all pure conjecture.

I'm not sure what happens when a city is destroyed (whether fertility bounds back up or not) or what happens when infertile terrain is transformed to fertile terrain. I have the feeling it stays at zero... But that would mean the AI won't build cities on terrain transformed to grassland. That can be tested.

:) Smiley · August 14, 2003, 10:09

This could explain why the AI doesn't do Infinite City Syndrome.

So hypothetically speaking, even if grassland produced nothing, the AI would build cities on that would promptly starve?

Mercator · August 15, 2003, 08:10

Yep.

Elok · August 15, 2003, 11:29

On a related note, if the AI had a city surrounded by horrible grasslands and super-upgraded glaciers, would it decide what squares to have its people work based on stats, or stick to its prejudices and get like 1 food from the grassland?

N35t0r · August 15, 2003, 16:24

it will probably choose the 'best' arrangement that it offers you when you click for deafult arrangement on your city screen.... it will probably go for the uber glacier (they _do_ exploit oilfield-deserts on scenarios, at the expense of farmlanded grass...)

Mercator · August 15, 2003, 18:30

I think HsFB is right there...

If the AI had a choice between irrigating one of those two however, it might follow the fertility values again in stead of the rules. That's just a hunch though.

:) Smiley · August 15, 2003, 22:21

Hmmm. I'll have to test that with UrbCiv. Does anyone know of any other comprehensive terrain mods and how they went?

N35t0r · August 15, 2003, 23:44

Quote:

Originally posted by Mercator
I think HsFB is right there...

If the AI had a choice between irrigating one of those two however, it might follow the fertility values again in stead of the rules. That's just a hunch though.

nah, i doubt they'd go against the rules... they'd probably go for the first, either mine or irrigate, according to the ai govt value on rules...

will experiment a bit...

N35t0r · August 16, 2003, 00:10

hmmm.... i modified the game so that glacier and mountain provide 9 food, and everything else provides 0 of everything....

the AI didn't build a city in an all-glacier continent, but it did in a grass tile with an adjacent glacier (which it tapped for food immediately, thus no starvation...)

it did also found a city on an all grass continent, which immediately died out due to starvation (no food source)

(note that the city square only adds one shield, never one food , if the city square doesn't produce each... thus un-shielded grass cities produce 1 shield, but mountain citied produce no food... not even 1 (with standard rules))

btw, the ai does specialists instead of placing unproducing workers on city tiles....

Boco · August 16, 2003, 09:20

Quote:

note that the city square only adds one shield, never one food , if the city square doesn't produce each... thus un-shielded grass cities produce 1 shield, but mountain citied produce no food... not even 1 (with standard rules)

In ToT, the city square bonus consists of the irrigated food value + 1 shield + 1 arrow

For ex,

Code:

;Name,      m, d,  f,s,t,   irr, f,#t,ai,   mine,s,#t, ai,xform,impassable 
@TERRAIN
Baadiyah,   2, 2,  0,0,0,   yes,10, 4, 0,   yes, 4,99,  0,  no,   yes, ; Drt

gives this

:) Smiley · August 16, 2003, 19:27

Wow thats a lot of munchies.

Boco · August 16, 2003, 20:10

Supercharged irrigation water out of the Elizabeth River.

Henrik · August 17, 2003, 03:12

Quote:

Originally posted by HsFB
(note that the city square only adds one shield, never one food , if the city square doesn't produce each... thus un-shielded grass cities produce 1 shield, but mountain citied produce no food... not even 1 (with standard rules))

The city square will add the amount of food that's given for the terrain if it's irrigated. If there's no irrigation value and the terrain normally doesnt give food, the city tile will not generate food.

(You can even insert a number here without allowing irrigation and still have cities generate that much food when built on the terrain).

:) Smiley · August 17, 2003, 10:46

While we're on this topic, is there a way of delaying irrigation to the acquisition of a certain tech?

Elok · August 17, 2003, 23:54

How about if you made irrigation give a bonus of 0, then let them research refrigeration? That's the only thing I can think of.

N35t0r · August 18, 2003, 01:44

of course, then the 'irrigation' would be limited to an extra 50% food....

Boco, i knew it irrigated, but i didn't know it also gave the bonus if irrigate was set to no but a value was given... i speak of, for example, mountain cities 0 food, 1 shield, 1 trade....

Boco · August 18, 2003, 01:53

The only catch I that I think I remember seeing is when you try to de-irrigate a terrain (Shift F8) that's set to no irrigation but with a nonzero bonus, ToT crashes. I believe that I had to change the @Terrain settings, make the change, and restore my desired @Terrain setting.

N35t0r · August 18, 2003, 04:08

well, i have MGE so i wouldn't know... but i think it doesn't crash like that in MGE...

:) Smiley · August 18, 2003, 19:04

I use plain vanilla CIV on the computer I'm at now, so I really wouldn't know then.