Updated to hopefully be a bit clearer.
This guide will assume you're just going to add
one province. I suggest you start off with that just to get used to the method before doing any more than that.
1. Tools required
This guide will be written with the assumption that you are using GIMP, Calc and the EUR Positions Editor.
2. Create a Mod Directory (aka "moddir")
Create a moddir using
this as a guide. It was written for EU3, but EUR works in exactly the same way.
In this guide, whenever I say "game directory", I will always refer to the location on your hard drive where you installed EUR (for me it's
c:\Games\Europa Universalis - Rome).
If I say "moddir", then I mean your mod directory that you created using the above guide (for me, the directory would therefore be
c:\Games\Europa Universalis - Rome\mod\MyMod).
In your moddir, create three new subfolders:
history
map
localisation
In your new history folder, create another subfolder called
provinces.
From your game directory, copy the following files to the equivalent folder in your moddir:
map (copy everything except for the subfolders)
localisation\text.csv
3. Create a new province in definition.csv
Go to your moddir\map\definition.csv file.
All provinces, both land and sea, must be defined in this file. Open it with Calc, and you'll see a dialog box called
Text Import. In the "Separator Options" section, un-check the "Comma" checkbox, and select the "Semicolon" box instead. Where it says "Text Delimiter", remove the character in that field so that it is blank.
In that file, you'll see 5 columns:
Province: this is the province's ID value ("provID"). You don't need to touch this column.
Red, Green and Blue: these are the RGB values of that province in provinces.bmp (we'll get to that in a minute). Every province needs a unique combination of RGB values.
Internal Province Name: it's not actually labelled, but that's what it is.
Land provinces are all listed first, followed by sea provinces, and finally blank "spare" provinces. Because land provinces must come before sea provinces, we have to push the sea provinces down one row. To do this, scroll down to
cell B271 and select it. Then, scroll down to
cell E337, hold down the SHIFT key and select that cell. Doing this will highlight all of the relevant sea province information.
Get a pen and a piece of paper and write down the RGB values of the line below this (68;250;250). This will be the RGB value of your new province.
Next, right-click the cells you selected and select
Cut. Scroll up to
cell B272: right-click it and select
Paste. Doing this means that all of the sea provinces have been shifted down one. Enter the RGB values you wrote down earlier into the empty cells above the sea provinces and enter in a name for your province as well (this name doesn't really do anything, it just helps you remember it).
Save this file and close it, you won't need to open it again.
4. Change the values in default.map
Go to your moddir\map\default.map file and open it with a text editor.
Change the
max_provinces value to 338.
Change the
sea_starts value to 271.
Save and close.
5. Make first edits to positions.txt
Go to your moddir\map\positions.txt file and open it with a text editor.
This bit is boring, so try not to snore.
Scroll down until you find the entry for provID #270 (just press Ctrl+F and type in
Sinus Tergestinus if you're using Notepad). For this province and every province after, you need to add +1 to the provID number.
So 270 becomes 271, 271 becomes 272, etc.
When you're done, save and close.
6. Add your province to region.txt
I actually forgot to include this step in my previous guide, it would have caused a crash during loading. Oops :wacko:
Go to your moddir\map\region.txt and open it. Find a region that is suitable for your province and add your provID to the list.
7. Add your province to provinces.bmp
Go to your moddir\map\provinces.bmp file and open it with GIMP. Have the RGB values you wrote down earlier handy.
If all you're doing is splitting a province in two (eg Crete), find the province you want to split. In the "Toolbox" pane, choose the "Select By Color Tool". Click on the province you want to split: the tool will now select only that province, meaning that when you try to colour in you own province, your province's colour will not spill into other areas.
With the province selected, go back to the Toolbox and choose the "Pencil Tool". Change the size of the brush to whatever suits you best, but keep Opacity at 100% and deselect any of the options.
Next, you'll need to change the foreground colour to the RGB value of your province. In the Toolbox, you'll see two rectangles: a black one overlapping a white one. Click the black rectangle, and enter the RGB values into the appropriate boxes (it should end up making a very light blue colour). Click OK and go back to your map and colour in whatever you need.
Save and close.
8. Add a new history file
Go to the gamedirectory\history\provinces folder. Find the file for the province you just split, right-click it and select
Copy.
Then go to your moddir\history\provinces folder, right-click anywhere and select
Paste.
Rename the file to
270 - province name (just use whatever province name you entered in definitions.csv in section 3). You can edit this later after you've tested your province.
9. Add new localisation for your province
Go to your moddir\localisations\text.csv file and open it with Calc/Excel, exactly as you did with the
definitions.csv file.
Localisation files tell the game how to display text in various languages. You probably won't need to bother with anything other than the English section, though.
Scroll down to
row 352. Right-click on the row number and click "Insert Rows". In the new
cell A352, type in
PROV337. Scroll across to
cell M352 and add an
x to that cell like all the others above and below it.
Click on
cell B351 (the name of the last sea province), scroll up to
cell B285 (the name of the first sea province) hold down shift and click it. This will select all of the sea provinces. Right click one of them, select "Cut"; right-click on
cell B286 and click
Paste. In the now-empty
cell B285, enter the name of your province as you would like to see it in-game.
Save and close.
10. Delete map cache and test your changes
Go to gamedirectory\map\cache\province_textures and delete all the files, but leave the folder itself intact. You won't need to do this again unless you add more provinces.
Go to gamedirectory\map\cache and delete all the files (but NOT the subfolder) in that directory. You need to do this every time you need to delete the map cache.
Go to moddir\map\cache and delete any files in there. You need to do this every time you need to delete the map cache.
Run the game launcher, select your mod from the drop-down menu and click Start. The game should load - if it crashes, take note of what the last thing the loading screen said and let me know.
If it works, then continue on.
11. Second edits of positions.txt
This time we'll use the positions editor

You will need the latest
Java Runtime Environment (JRE) for it to work.
In the directory where you installed the editor, there is a file called
config.txt. Open it and follow the instructions in there.
Run the
EUR_positions_editor.jar file. Find your province and double-click it - the rest of it should be fairly straightforward. Don't worry about "City nudge" and "Trade nudge" (I don't even remember what those do). Click on "Edit Position" then click anywhere within your province to place that object there, easy. With the port (if applicable), place it about 2 pixels into the sea.
Port rotation is the only tricky thing, I stuffed up the code somewhere and am too lazy to fix it

The actual direction the port faces is, IIRC, another 90° clockwise to what the text shows.
Save and close. Delete the map cache again and load the game with your mod to test it out.
At this point you can pretty much call it a day and it'll work. All you need to do is edit the province's history as necessary, but really all you need to do is tweak the population numbers etc to make it balanced.
And I think that's everything. It is now ridiculous o'clock in the morning and I need sleep, so if I missed anything I'll update this post later.