Identical Map Generation (not random!!)

I'm not certain if this is a bug. In fact, I may just be failing to do something correctly here, but...

I've now attempted to load a custom, standard, continental, temperate, average sea level world 7 times now. Every time I get exactly the same map. There isn't a place to pick a random number like in Civ III. Every time the game loads, even when I choose different civilizations to start with, my settler and warrior appear in the exact same spot on the exact same continent. Everything is exactly the same except for the civ type.

Am I missing something, or are other people seeing this?

Obviously, the map generator is a step backwards.
It happened to me as well, that I got the same map several times. Sometimes, the coverage is different, but the scape is the same, sometimes it is just 100% identical.
This is more than annoying - and don't somebody try to explain this with rushing the game.
It has been reported that the game was under development for more than 18 months now, and for sure the map generator is not something to finish at the last minute.

Is is possible that something is getting cached and not cleared properly? Try removing the files from the cache directory (save them some place else).

C:\Documents and Settings\username\Application Data\My Games\Civilization 4\cache

Alternatively, have you made any modifications to your ini file? This particular setting peaks my interest...

; Random seed for map generation, or '0' for default
MapRandSeed = 0

I have not touched my ini file or any other aspect of the internal workings of the game. I opened the box, installed the game, updated my drivers, and then played for the last 48 hours. I haven't had significant trouble, so I've spent all my time in-game until now. I've tried this with several different settings now, and the same thing happens... I get identical maps produced every time I use the same settings. This is beyond annoying, because one of the things I found attractive about Civ III was that the game could be new every time. When you already know the map, there is no way it can be new. I enjoy the game except for this problem.

I'll try your suggestions and see if it changes anything.

This post was more of a question than anything else... is this a bug I'm getting which is unique to my machine and setup, or are other people seeing this too? Have you guys noticed this happening to you in-game?

I had this happen to me. I started a story at another forum, and 3 other users reported the exact same map that I had. Some proof. The top is my map, the bottom is another player's

Ignore my previous post. I recognize that map, Washington is where my civ started.

why is it that the more I read here on the forums, the more a sinking feeling I get. Now, this is really a terrible joke....

That was my first map, too.

I'll post a screenie tomorrow. (posting from work now, on dial up at home).

I also played on the exact same map today! With the same starting location of the civs (Madrid, Timbuktu and Kyoto.)

So, we may assume that the map generator (which was quite good in C3C), now doesn't work "randomly" anymore, but get's its results from some limited set of values.

Argh. I really don't understand how they could mess up even this?

I'd suggest posting a question here where you can talk to the map script creator.

-- Ravensfire

In Pascal terms I think they simply forgot "Randomize;".

Matrix said:

In Pascal terms I think they simply forgot "Randomize;".

Click to expand...

Um... no.


I've run some tests here at home, on my own machine, using my copy of the game purchased at the local Electronics Boutique.

I launched eight maps on identical settings: Continents, Small, all defaults.

The first four passes, I used the Custom Game option:



The last four passes, I used the Play Now option:



Passes 1 and 2 were created via Custom after launching Civ4 from my Desktop.

Passes 3 and 4 were created via Custom after exiting to Main Menu, after ending the previous pass.

Passes 5 and 6 were created via Play Now after launching Civ4 from my Desktop.

Passes 7 and 8 were created via Play Now after exiting to Main Menu, after ending the previous pass.

Eight games launched, eight completely different map results:



The only indication I have of any trouble is that the first Play Now map in my sample is the same map configuration shown in Super Beaver's screenshot. That will occur if the same seed is used to create the map.

Is there a bug with the random seed generator? Resetting itself under some circumstances? Or on certain people's machines? I don't know.

Whatever the problem is, it lies with the random seeding, NOT with my maps!

I'll do what I can to look in to it further.


Meanwhile, can those of you with this problem verify that you did not fiddle with the seed numbers in your ini files? If not set to 0, you'll get the same seed over and over (identical map each time). Thanks!

Those of you who -are- having this issue should be able to work around it temporarily by manually choosing different seeds and setting them in your ini file. Go to Config in your root Civ4 folder and double click to open it.





If the MapRand is not set to 0, then that's likely your problem. Set it to 0 and try again. If it -is- set to 0, then set it to a random number pulled out of thin air: something large, like five or six or eight digits. Reset it each time you want to replay on the same map script. Again, this is only meant as a temporary workaround until a more permanent solution can be found.

This issue is a bit of a head scratcher, as no sign of anything of this kind has ever showed up for me -- and still didn't in my testing just now. I've run hundreds upon hundreds of tests, including sometimes thirty in a row on identical settings, and never seen a duplicate. The random number generator is not my direct responsibility, though, so all I can do is pass on your reports.


I hope this reassures most of you. Sorry for the troubles!


- Sirian

Might be the cause Sirian - there's been a lot of people wanting to turn-off preserve random seed - perhaps they thought that was what they were doing?

ainwood said:

Might be the cause Sirian - there's been a lot of people wanting to turn-off preserve random seed - perhaps they thought that was what they were doing?

Click to expand...

If people have set that value to 1, thinking they are toggling a boolean flag, then yes, they are messing things up all on their own.

There is no option to turn off Preserve Random Seed.


- Sirian

I can assure you, Sirian, that I had 2 times identical maps.
First time they were completely identical, the next time they were equally shaped, yet the coverage was different.
I didn't play around with the .ini-file.

In my case, this four games equal to ~5% of my games.

My assumption is that the map generator sometimes runs "streaks" of equal seed numbers. For sure it creates more similar maps than it did in Civ3, so the algorithm seems to have changed since then.

[edit]Forgot to mention, that I just run huge maps, the continents settings.

Commander Bello said:

My assumption is that the map generator sometimes runs "streaks" of equal seed numbers. For sure it creates more similar maps than it did in Civ3, so the algorithm seems to have changed since then.

Click to expand...

Civ4 uses the same Pseudo Random Number Generator as Civ3. At least that is my understanding.

5% duplicates? That's probably of more concern than 100% duplicates, which would clearly be a bug, and probably an easy one to fix, once identified.

The more data we get on the issue, the closer we come to understanding its nature, so anybody experiencing duplicates... please report them here! Thanks.


- Sirian

Oh One More Thing(TM)...

Four games is five percent of your games?

Have you really played eighty games already?

Sirian said:

Oh One More Thing(TM)...

Four games is five percent of your games?

Have you really played eighty games already?

Click to expand...

it would be enough to just generate 80 maps, without actually playing them through, wouldn't it?

Sirian, thanks for you thoughtful and quick response.

Something unusual has happened... I can now generate random maps. This is strange because I don't know why I couldn't do so yesterday, but I suddenly can today. So, without further ado, here are the things I did, in the order I did them. Perhaps this story can help someone figure out what the problem is (if there is one).

1) I bought the game from the store, installed drivers, and sat down and played my first game. I went to "Play Now, and selected continents, temperate, low sea, ancient era, standard world, normal speed, with a random civ. I lost, by the way, but had lots of fun learning.

2) Now, almost 48 hours later, I start my second map. Again, I went to "Play Now" and selected continents, temperate, ect... identical specs. I got the exact same map with a new civ. I figured this out almost immediately, but just to make sure I wasted a few turns running my scout around and removing the fog of war. Yep, it was identical. So I do this five more times, and get exactly the same map. At this point I was unhappy.

3) I came to these boards and made my post, then went to sleep.

4) The next day I saw a link to the following post: http://forums.civfanatics.com/showthread.php?t=134226 which directed me to try doing 'tilted-axis' with all random if I wanted a random map. I tried that, and got random maps. This was exciting, so I messed about with this maps, attempting to refine my starting strategy for playing Civ IV by making multiple maps with identical specs and playing them for 100 turns or so. I made close to 20 maps, and they were all different.

5) I came back to this forum and saw all the posts, so I decided to try and replicate my initial problem. I went back into the game in "Play Now" and entered the origial specs for the map. Now I get random maps.

Ok, so it isn't an exciting story. The only thing I did was go into "custom/tilted axis/random all" a few times. Then when I went back to "Play Now" I could get random maps.

Correlation is not causation, so it may not mean anything, but is it possible that doing the "tilted/random" thing fixed my "play now" problem?

I don't know, but I'm just glad I can play exciting games now. I'm not sure this is of any use, but thanks for reading!