Honours Blog #22 – Modding Process: Provinces

Welcome to the second part of the Modding Process posts! These posts will go in-depth on the actual steps used as well as any considerations that need to be taken when doing it. This time I’ll be covering one of the most important aspects of EU4 Modding: Making Provinces, covering both the drawing of provinces on the provinces.bmp as well as the actual editing of the province stats itself (which was partly covered here).


Provinces Process

Drawing provinces is exactly what it sounds: drawing a shape (of a province) on Photoshop! As mentioned in the EU4 Map Modding Basics each province has its own unique RGB and ID which is stored in the adjacencies.csv file – for ease of development I kept the vanilla adjacencies and use the same RGBs they used so I can essentially copy the colours on the vanilla provinces.bmp and draw them onto my own custom one. Because of this any provinces I draw on my map will have the same statistics and name as their vanilla variant (eg if I take the RGBs for Paris and put it in my map, i’ll have the province of Paris in my map).

For this process I use Photoshop which has my master file containing all the maps and my provinces numbers.psd which contains a map of the vanilla provinces and their IDs. For editing each individual province file itself I use Notepad++ as well as the Clausewitz Scenario Editor.

Drawing the Province

  • 1. Use the Photoshop Eyedropper tool on the provinces numbers.psd and select the next ID onwards’ RGB (I go in numerical order to organize it, eg draw province ID 1 then ID 2, etc)


Drawing a province – led by an outline to be filled in soon after – note the transparent map so I can see any terrain below
  • 2. Draw the province using the RGB on the master file, for considerations:
    • -Density: the more developed or populated a province is usually dictates its size. Developed regions have smaller provinces whilst less developed ones don’t. Compare for example Europe vs the Mongolian Steppes.
    • -Natural Borders: compare with the terrain and rivers map and see if there are any hills, rivers or forests nearby that could dictate the shape of the province
    • -Internal or External: is the province well within a country? If so it doesn’t need to adhere to natural borders and can be more messy. Provinces that form the borders between two independent countries are more likely to adhere to Natural Borders as they are more defensible and a clear boundary
    • -General Vibe: not so much worldbuilding but just pure design. Is the province aesthetically pleasing/believable? For example we might have multiple provinces that are drawn vertically and look odd – why not throw a horizontal one in there to make it less like a stack of canned sardines!


  • 3. Check for any mechanical inconsistencies/faults by loading the game. Common ones include:
    • -Incorrect RGB: likely due to human error, game works but will just be an empty province
    • -Duplicate RGB: again human error, game works and province just appears twice as the same entity
    • -Stray Pixels: causes provinces to have small holes in it and look odd, can be fixed by simply going back into the photoshop file
    • -Barbed/Sharp shape: caused by drawing the province too oddly, for example a really long 1-pixel wide line that just shoots out from the middle – as a guideline I try to keep provinces as naturally smooth as possible (it’s okay for it to look slightly odd but you can generally tell if its too much)


Editing individual provinces

  • 1. Open up the Clausewitz Scenario Editor and select the province which should open up its history file


  • 2. Replace the contents with a template from an existing modified province (eg copy and paste another province’s contents into it)
(Left) Vanilla Provinces file, (Right) Modified Provinces File

In addition to this I looked at existing provinces to see their stats to help compare better:

  • -Paris has: 11 Tax, 11 Production, 10 Manpower (near our timeframe, the 1500s, Paris had around 225,000 people living in it)
  • -Venice has: 10 Tax, 12 Production, 5 Manpower (around 110,000 people. Note how Production is higher than Paris, possible due to its status as a mercantile city)
  • -London has:  8 Tax, 8 Production, 6 Manpower.
  • -London in 1741 has 18 Tax  18 Production, 8 Manpower. (London was the most populous city in the world bar Beijing, with an est. 700,000 people at this time)

Manpower is quite confusing as I originally thought it to be how population-dense a province is, but after looking at the Chinese/Indian provinces (which have a lot of people historically) they usually have 1-2 average Manpower so that obviously wasn’t the case! In the end I couldn’t find a clear definition so settled on one: the amount of fighting-fit population (this explains why high Tax/Production and historical population provinces like Chinese Nanjing with a whopping est. 487,000 population only has 3 Manpower in EU4. After all, the Chinese were known for their Confucian Bureaucracy and focus on trade whereas Europe which has higher Manpower provinces as it was all about its knightly warrior-castes, feudal wars and peasant levies)


So in terms of considerations the most important things are:

  • -Where is this province: if its a developed part of the world its got higher Tax, Production and Manpower (from vanilla province the former two usually go hand in hand, eg if a province has 8 Tax it has 8 Production).
  • -Whats the terrain type: provinces in less hospitable terrain (hills, mountains, deserts) will have lower stats whereas flatlands, coastal and river provinces will be higher (flatlands as its easier to build on, see Northern Italy – coastal as it has access to sea trade – river as it has access to river trade)
  • -What trade goods do they make, this is usually dictated by environment: (info taken from vanilla EU4)
    • -Glass, Paper or Cloth: richer urban provinces
    • -Grain, Livestock and Wool: poorer rural provinces, wool is seen in mountainous/hilly terrain
    • -Fish: coastal provinces
    • -Salt: either from some marshy provinces or from mines (can be anywhere, though mountainous/hilly terrain works well)
    • -Wine: southern/mediterranean climate provinces, usually along rivers
    • -Iron/Copper/Gold: Mountains or hill provinces
    • -Naval Supplies: some coastal provinces, or wooded inland provinces (aka strong wood for ships)
    • -Spices/Cotton/Sugar: can take place of the other rural trade goods in southern regions, Spices dominated Indonesia in history
    • -Tea: Hilly/mountainous regions of the East
    • -Tropical Wood: Forested areas of the East
    • -Gems: usually mountainous provinces, very rare!
    • -Silk: its from silkworms so the China-equivalent, though silkworms can be stolen and taken anywhere as the Byzantines did in history
    • -Chinaware: rich urban provinces in the China-equivalent, though my setting has no equivalent so maybe elven provinces?
    • -Dye: seen in Indian provinces so their equivalent in my world
    • -Incense: seen in Arabia and the East
    • -Ivory: seen in African climate regions
    • -Slaves: seen in Africa, either major sources of slaves or major slave-trading hubs. In my setting it’ll be different, the Gnolls were known slavers so their provinces will be sources of it. The Orcish Greentide will also end up with many orcs being enslaved both by their opponents and other orcs themselves.


Adding provinces to areas and regions

Each province belongs to an area, and multiple areas belong to a single region. Each region then belongs to a superregion and each superregion belongs to a continent!

For example, the province of “London” belongs to the “East Anglia” area, which belongs to the “Britain” region, which belongs to the “Western Europe” superregion which is in the continent of “Europe”.

(Left) Area Map, (Right) Region Map in my mod
(Left) Area File, (Right) Region File

Determining what provinces fit in each area is dictated by not only geography (eg they are nearby, they are all in a forest, they share a river, etc) but also culture (same peoples) and owners.

Areas form the administrative regions of EU4, in which they can either be a territory or state.

A territory can only contain temporary cores (ie they are lost when the province are lost) but can be turned into a state and gain permanent cores (though you can only have a certain number of states).

Owning all of an area is advisable as it allows you to enact Edicts that affect a wider amount of provinces as well as the fact that states can also have lower autonomy, meaning they are more efficient at generating income.



Etext.org (2007). Available at: https://web.archive.org/web/20070929110844/http://www.etext.org/Politics/World.Systems/datasets/citypop/civilizations/citypops_2000BC-1988AD (Accessed: 21 November 2017).

Ming dynasty | Chinese history (2017). Available at: https://www.britannica.com/topic/Ming-dynasty-Chinese-history (Accessed: 22 November 2017).

Honours Blog #21 – Rivers Clarity/Design on the Map

Just a quick one here, I was looking at the Halfling Small Country that makes the border region between Lorent and Gawed and realized that you can barely see the rivers that determine the borders! This is bad in terms of design as you can’t really tell “why” the borders are there at a glance when you should be able to tell that they’re there because of a natural river boundary.

This was because I drew the provinces map perfectly in line with the rivers which meant due to the way country-to-country borders are drawn on the map you could barely see the river itself!

(Top) Old Map, (Bottom) New Map with clearer rivers

The core of the technique was to look at how Paradox handled their rivers-province interaction.

For them they don’t adhere to a pixel-perfect province boundary, essentially some of the province would overlap to the other side of the river just so you can see the river below the border much better. As you can see the bottom one has that and hopefully its much easier to tell that the borders here are dictated by the two rivers (the left one flowing west from Royvibbob to Southroy and the right one flowing from the top right down to the Saltmarsh provinces)

Honours Blog #20 – Modding Process: Rivers & Revamping Corvuria

Haven’t posted in a while but I’ve done quite a bit since the last post so I have a bit of a backlog to fill!


Shrinking Corvuria

One of the places I’ve not talked about is Corvuria, which draws a lot of inspiration from Transylvania and the Carpathian Region: a large mountainous shield with vast unforgiving forests, plains and marshland.

As such Corvuria served as border between the Dameshead Region and Sarhal (the southeast) and I had a large unforgiving swamp taking up most of the place. A deadly location felled and dissuaded many armies that tried to march across to reach the other side.


However I realized that Corvuria would be a massive country in the map but have very little depth to it in terms of provinces as over 3/4 of it would be barely hospitable marshland!

(Left) Old Corvuria, (Right) New Corvuria

Therefore I ended up moving the mountain shield border down and shrinking the marshland (known as Daravan’s Folly) by about 1/3, this ended up with:

  • -a smaller marshland but still served the purpose of being a deadly crossroads region
  • -a (slightly) smaller Corvuria on the map which makes it more reasonable with its actual strength as a country
  • -more space for Escann (Eastern Cannor) meaning more space for Greentide-related action and countries! (probably the most important thing here)


Rivers Process

With the modification of the Corvurian region I also needed to change the rivers that flow throughout the province, so here’s a look at the process surrounding that.

As mentioned before you have to be pixel-perfect with the rivers as well as having to stick with the specific color index required by the game.

(Left) Rough Rivers, (Right) Refined Rivers

When I place new rivers I usually have it overlayed ontop of the terrain map. This is so I can use the terrain map as a reference to influence the flow and direction of rivers, for example: rivers flow from high ground so they start at mountainous regions (the white bits) and they always flow to the path of least resistance, meaning that we have to avoid any hilly terrain and the like (the dark green bits). In addition to that I use the rivers as the border of the Daravan’s Folly marshland.


  • 1. My first step is usually drawing a rough outline of the river paths, not caring about being pixel-perfect but just to have an overall feel of where the rivers are going and where they cover


  • 2. After that I zoom in and go into detail to refine it all, enforcing the 1-pixel-width rule (as they won’t be registered otherwise) and adding the various connectors for converging rivers (the red pixels). During this time I also change river depth using the different colors available (darker blues means thicker and deeper rivers).


  • 3. Then I load up the map to see if they appear – if they don’t then its either:
    • -a portion of the river is 2 or more pixels wide, not adhering to the 1-pixel-width rule
    • -a portion of the river isn’t connected properly (no corner/diagonal connections!)
    • -a red/yellow connector pixel isn’t properly placed
    • -a green source pixel isn’t in place (rivers need 1 green pixel to just tell the game “this is where the river starts”, a huge river with 7 smaller ones connecting to it still only needs one at the start of the huge river)




Honours Blog #19 – Modding Tools Overview

So i’ve talked a fair bit about modding, but what do I actually use to make it happen?

For Paradox games all you need is a text editor and an image editor to make it as easy and as accessible as possible, but what exactly do I use?


Core Tools


Note the many layers used to the right, allowing me to cover and refer to multiple things at once

While Paint works Photoshop has some nifty tools and tricks which makes it easier to work on the map files. It allows layers which allows me to have every single map file on the same photoshop.psd as well as transparency which helps a lot when overlaying different info ontop of each other (like place names and rivers ontop of the terrain).



Flavour Events for England with colour’d syntax


Instead of using Notepad, Notepad++ is a very lean and light text editor that turns it into a more programming-oriented one, making the large text files much more readable! With this you can also get Paradox Script syntax which colours said syntax in as you would if you were programming in an IDE and using a more mainstream language like C#.

I tried to use other text editors like Atom but they didnt have a compatible Paradox Script syntax so, while prettier, Notepad++ does the job just as good.



The mod’s git repo as of posting

My source control solution. I used this last year for my 3rd year group project so i’m fairly comfortable with it – GitKraken is also fully user-interface so I don’t need to use the .git command line interface which I have no clue on how to use!

As for half of the week I’m away from my flat I can use this to stay up to date and work on my laptop instead. Also, given the dependency-led crashes that EU4 modding has I can always revert back to a previous version if it ends up that bad.


Community-Made Tools

EU4 Provinces Colorpicker

EU4 Provinces Colorpicker website

A nifty website that has every single province in the game as well as their respective ID’s and unique RGB colour schema.

I mainly use this to refer to when i’m working within photoshop if I don’t know what ID a province has but I know its RGB colour – it also has the ability to generate a new colour that isn’t used by the game already.


The Validator

Audax Validator being used on the mod

A really useful tool that essentially finds bugs and errors and highlights them to you. Will be increasingly useful as the mod gets bigger and bigger and if any compatability issues arises from new game versions.


Clausewitz Scenario Editor

Provinces map with selected Wesdam province and its history file

A new tool that I haven’t had a chance to use yet. It allows you to look the the in-game map and its different mapmodes (eg province map, trade goods, religions, etc) without actually opening up the game.

This will allow me to fill out the custom provinces history without having to open up the game itself (which is pretty slow if I use my laptop) and edit it right then and there. This will also help negate the cross-referencing needed mentioned in the EU4 Provinces Colorpicker above as you can get all that info in the editor instead.

Honours Blog #18 – First Meeting with Supervisor

So yesterday I had a meeting with my project supervisor, Darshana, just to give him a brief overview of what the project’s gonna be and what the dissertation will be about.

While he did say that the dissertation question was a good basis to go with (here), I did mention the recent feedback from the presentation as well as my own thoughts that it needed to be changed and refined a little bit more; namely the move away from the mechanics aspect to more about limitations and worldbuilding processes themselves.

Other than that the modwork is going along well, I personally think the real issue for this (at least for now) will be defining the dissertation questions and having more varied blog posts here that isn’t all about modding but more about worldbuilding research.


  • -Comparison between different types of fantasy fiction, eg what makes the world of the Witcher different from D&D? (Low Fantasy vs High Fantasy research)
  • -How do we define what a limitation is?
    • -maybe making a design document that isn’t EU4-specific will highlight technical limitations?
    • -other technical limitations include getting new 3D models (eg to represent orcs), how do we represent different races living in the same province? Magic?
  • -In general more posts about worldbuilding and its related research processes and inspirations
    • -for example, a post about halflings in my world and comparisons with different depictions of halflings in other settings + real world inspirations
  • -Not from the meeting but I just realised that what i’m aiming for here is to create a world that supports an emergent narrative (its a sandbox game after all!) so research and posts about that