Now this is seriously messed up, just look at this:

http://img87.imageshack.us/img87/3455/civ4screenshot0005ij6.th.jpg (http://img87.imageshack.us/img87/3455/civ4screenshot0005ij6.jpg)

Background Infos:
We are Portugal and are playing an OCC (One-City Challenge). Portugal just signed a Permanent Alliance with England. Before this the Pig and the Forest Preserve NE of the Pig belonged to Portugal (and it's still 98% Portugese and only 1% English). However, since the PA was signed, for some oddball reason these EXTREMELY IMPORTANT tiles of Lisbon's BFC (Big Fat Cross) have now been transfered to England. What the ...?

I don't mind England taking control of any of my Tiles outside our only City's BFC (since they will always give us any resources we ask for anyway), but we seriously need our BFC intact. This is our only city for goodness sake!

This has to be a BUG? What can we do about it, how do we fix this (we want our BFC intact!)?

Interesting problem. I think I saw this happen to me when I signed a PA before too, but IIRC the tiles switched back to me later.

I tried spamming 20 or so GA (via the World Builder) and used them for Great Works. The tiles did NOT switch back to me. :'(

And like it says, they're already 98% Portugese (and my Culture is about 10x the culture of the two English cities in the picture, combined).

It seems the contested BFC tiles were set to some kind of 'fair' deal. Obviously not based on culture, as in that case you would had it. It's resolved in favor of the closest city perhaps: The forest preserve and the pigs are closer to York than to Lissabon.

Seems to make sense for team games in general.

This is quite unfortunate for a OCC game of course...

Maybe it has to do with that "fix" they made where a vassal's borders could never be in your BFC. In this case it seems like the game thinks you are England's vassal from a border perspective.

Edit: Just saw that you have tiles from London so this can't be the case. Agree with above post

So I can steal all his resources, money and GPT, but not defend my Capital's BFC? Makes sense...

Anyway, I think Refar's explanation sounds about right.

The question is if you can steal his cities (if you can flip-destroy London, etc.)

The question is if you can steal his cities (if you can flip-destroy London, etc.)
That wouldn't be very nice, now would it. (WB -> ERASE MODE)

Hmm, I think I'm just gonna give me a fish or two to compensate (cheating I know, but this was a very weird consequence and had I known about it in advance, I wouldn't have played "suck up to England" for four thousand years--rationalizing is the sh1t).

A Permanent Alliance changes the border calculation mechanic by design. You get all the tiles in your BFC that aren't in any of your partner's BFCs. It's been that way since Vanilla.

If the BFCs overlap, then they go to the closest city, which has the effect of smoothing the border. If they are equidistant, then possibly culture rules. Try deleting York in the World builder and see if the pigs flip back to you.

Out side of that, the only way to get the pigs back is probably to culturally revolt and autoraze York.

What if you just change territory to yours in WB? Does it switch back on the next turn?

When the Permanent Alliance is signed, cultural domination of a tile is thrown out the window. Since this is now your teammate, the game will maximize the tiles available to each city.

When the cities are far enough apart, the border may be pushed back to allow full usage of the BFC.

When the cities are close enough together that the BFC overlap. A couple of things happen (based on my observations):

1. Due to city placement proximity rules, you are guaranteed to get the 8 tiles around the city. Cultural borders will be rearranged to satisfy this.

2. If one city of civ A and one city of civ B are both trying to get the tile, I have noticed that the human player will usually get the tile.

3. If one city of A and two cities of civ B are all trying to get the tile, then civ B will get the tile.

#3 is the case regarding the pigs in the OP situation. Both York and London have the pigs in their BFC. While you lost this one tile, you picked up all of the other contested tiles (except the ones affected by #1).

How the hell are you teching steel and have a size 24 city in 350bc?

The time / turn counter seem messed up in the screenshot. It Shows Turn 1 from 1500 which is usually not 350BC...

Thats an early pm, never seen that before. Usually I only see them very late, but then again I just started playing.

Turn counter is messed up. The Year is not however. And it's on Deity OCC. Won the game btw (Domination)! :D

ChicagoCubs :: Thanks a ton man, indeed that seems to be the case!

oranges :: Borders are reassigned every game turn.