Preventing City Founding

[William Keenan]

Awhile back Capt. Nemo was looking for a way to prevent the AI from founding new cities. Was a solution ever found?

[Henrik]

I don't know about Captain Nemo, but I came up whit a (sort of sulotion) in the scenario I'm making, the problem solved itself really, I built 255 cities (not on purpose, but it turned out that way), so the AI and the human was unable to build cities.

[techumseh]

Well Henrik, I have a more practical, though less than perfect solution. It's not original as it appeared in these forums several months ago, posted by someone I don't recall. The AI will only found new cities on grassland or plains terrain. So if your scenario allows you to give up 2 terrain types, just substitute tundra and glacier. Change the graphics and the characteristics to match grassland and plains. It's hard-coded so it doesn't matter how fertile you make them, no settler will found a city. They will build roads and forts. I haven't noticed irrigation, but I haven't really tested it.

[Kull]

That really is a cool idea, Techumseh! Taking it one step further, you could have scenarios which allow for AI city growth, but you CONTROL where they build them by placing "real" grassland squares in desired locations only.

A good example of this would be Imperium Romanum. If Bebro used the above method, the AI civs could be prevented from founding cities in most of Russia (but not the Crimea) and North Africa (except in historic locations on the coast). Really a great way to prevent the AI from running amok!

[BeBMan]

It seems to be a good solution. But wouldn´t the AI have lots of settlers running around on the map searching for a place for city founding?

[Panda]

Credit where credit's due, this is thanks to Dusty. I believe this is the topic you had in mind, tecumseh http://apolyton.net/forums/Forum18/HTML/001104.html

I've yet to try this out, but I doubt the "fertility" flag is dynamic. I think it more likely that only those grassland/plain squares when you first create the game will have this value, so if you edit that grassland square to arctic, the AI will still build there. If it can be controlled this way; tecumseh's findings suggest it can.

edit: actually, thinking about it, the reason tecumseh noticed only forts and roads and not irrigation may be attributed to the values set in the rules.txt where you can tinker with the minimum government needed for a particular improvement to each terrain type.
[This message has been edited by Andrew Livings (edited February 27, 2001).]

[Kull]

Andrew: I remember that thread, but at the time it seemed impractical. Imagine using the hex editor to change most of your grassland/plains squares to "F0". Ugghh! And how would you ever keep track of which is which while within the hex editor? (ie the ones you want cities built on versus the ones you don't). Utterly unworkable. Tecumseh's concept is much simpler to implement, since all that's required is a change to the rules.txt and terrain1.gif files. The only question is, will the AI irrigate? Hopefully you're right, and it's just a matter of adjusting the government modifier.

BeBro: There may be a few AI settlers wandering around, but no more than normal. I've never really checked this out, but I'm pretty sure the AI is restricted to one active settler per city. Therefore by limiting the number of cities they can build, you'll automatically cut down on the "wanderers".

[Mercator]

The idea is actually much more ancient and sort of common knowledge (although Dusty was the first to get the technical details right): http://apolyton.net/forums/Forum4/HTML/000491.html
I used the method in my Orbis Terrae scenario to prevent city building.
In case you're interested, I recently dug a little more into the exact encoding of maps in savegames (an earlier version can be found here: Map Encoding in Savegames, it's also part of Allard's "Hex Editing" doc). I might update it with my more recent version. I found more info, especially concerning fertility.
Another thing, there's a utility called MapCopy (should be in the database) which can copy fertility information between maps/savegames. When you use that, you can make a map where all fertile terrain is grassland and the rest, say, glacier. You can then copy the fertility info of that map into the savegame. That a whole lot easier than changing the hexes by hand! Even more, this method could also allow you to have the AI build cities on all kinds of terrain (not just whatever's in the grassland/plains spots). For instance, you could get the AI to build a city on a mountain (like Gibraltar or whatever is appropriate).
[This message has been edited by Mercator (edited March 01, 2001).]

[Kull]

Mercator: I forgot about that feature of Mapcopy! Your idea is an extremely elegant way to solve the problem. It's fast and relatively easy to pull off! For those who haven't used MapCopy, it's a tool that lets you edit your scenario map offline in the Map Editor program and then copies the changes (or SOME of the changes, as Mercator advocates above) back into the scn file.

[Mercator]

I updated the Map Encoding file.

[Heresson]

Originally posted by Henrik
I don't know about Captain Nemo, but I came up whit a (sort of sulotion) in the scenario I'm making, the problem solved itself really, I built 255 cities (not on purpose, but it turned out that way), so the AI and the human was unable to build cities.

But then, don't You get the annoying "too many cities" message?

I did. And in Fading Lights, I had to spot the points most likely to become spots on which AI would like to build cities, and se the events to changeterrain them every turn.