Crowqueen
Token forum woman
There is a Creation and Customization forum here that might be able to answer that better than us. Welcome to the forums, BTW.OK a change to my question, I know to modify most things you do so in the XML file and I have been able to modify a few things such as the default color of certain civilizations, move points but what I can't figure out is how to make a unit specific to only 1 civilization and how do you change the units you start out with, both the kind of units and how many?
Thanks
@Copywriter
1. Yes. You begin with the borders 1 tile in each direction like so:
E---E---E
E---C---E
E---E---E
(where E is Expansion and C is City)
Then when your borders expand once, you get
X---E---E---E---X
E---T---T---T---E
E---T---C---T---E
E---T---T---T---E
X---E---E---E---X
(where X is eXcluded, E is new expansion and T is a Tile already covered, C of course is your city). This second expansion is your Big Fat Cross, which is the area which your city can work to produce



After that your city's borders will go on expanding (exponentially slower) but your city cannot work tiles outside the BFC, although it can connect up resources. You should lay your cities out so that few tiles are outside the BFC of one city, otherwise you will waste a lot of land that could be made productive and increase the distance from your capital which will cost maintenance. Sometimes it is beneficial to overlap cities' BFCs but in the main I prefer to tessellate the cities and make sure that each city has the maximum space possible to work and develop their own tiles.
2. No. On land maps or maps that have finite boundaries (most continent/sea maps have ice at the poles so it is impossible for this to happen normally) you will need to take that into account when placing cities. I don't know many people here who play land maps so I am not sure what to suggest, because to be honest it depends on resources I need to harvest (e.g. if there is an iron square one from the top of the map I will put a city down next to it in order to connect it up, usually with the iron in the first 3x3 grid rather than the second BFC) but again, what is best at the time is best at the time. If it is a late-game city usually you don't lose much by plonking it down, but an earlier city is best given plenty of space to grow to at least its BFC area so I would avoid putting anything down in the top two rows of a map before you have a wide and diverse empire itself.
3. You wouldn't be able to trade it if they weren't able to research it. So if you can trade it to them - that is, if it shows on your side of the trading screen - it is possible for them to research it.
For example, take the following technology progression: Metal Casting leads to Machinery leads to Engineering.
Suleiman doesn't yet have Metal Casting, whereas I have Engineering. When I trade with Suleiman, all that shows on my side of the trading table is Metal Casting. I can't trade Suleiman Machinery until he has Metal Casting, and I can't trade him Engineering until he has Machinery. (This happens, BTW, because the AI doesn't seem to prioritize Metal Casting even though it is usually a vital technology if you want to get ahead in warfare.)