For the past 1-2 weeks i’ve been working on a Vertical Slice for the mod as well as getting back into EU4 modding in general. I’ve shown off what I had so far in Honours Blog #10 so this post will cover mostly the creation of my own custom countries, provinces, cultures and religions as well as the localisation related!
And if you’re curious, here’s what it looks like in-game so far:
For the sake of simplicity i’ll be covering how I made one of each of the examples above
Making a Country
Thanks to Cyridius’ guide on Making a Nation this was pretty straightforward, with the only real issues being the multiple files needed for making a country:
So to make a country you need:
common/countries needs a text file with the country name, eg “Lorent”
common/country_tags needs to have the new country’s tag added, eg “A01 = ‘countries/Lorent.txt'” meaning tag A01 leads to the Lorent file above
history/countries needs a text file with the tag and country name, eg “A01 – Lorent”
gfx/flags needs a .tga image file named as the tag, eg the image “A01” will contain the flag graphic for Lorent
Making a Province
In addition to the provinces RGB map you need a .txt file that links to each RGB value, and within that .txt file is the modifiable stats and variables relating to the province. For example the “38 – Riga.txt” relates to the province of Riga.
The text files to the left show two versions of Riga, with the first image being the original vanilla province and the second being a modified custom version
As you can see instead of the owners being RIG (aka Riga) it is now A01 (which in our case translates to Lorent)
Several other things have been changed such as cultures and religions (which we’ll get to later) as well as the three main stats: tax, production and manpower – as well as thr type of trade good
Some stuff remains unchanged like the capital = “Riga” but will certainly be changed once I come up with names (note capital = “Riga” does not change the province name but acts like a description)
There’s other special modifiers here too like the dauvaga_estuary_modifier – when I make a province properly i’ll either have to delete these (if the province has no estuary, which is likely the case) or make my own modifier which is as simple as changing the name, for example test_estuary_modifier.
As i’m not remaking the definitions (which had province IDs and RGB values) I need to keep the default province names, apparently if I rename “34 – Riga” into something else the game won’t recognize it and just use the vanilla “34 – Riga” file
Making a Culture
Each province has a culture, and each country has a primary culture and accepted secondary cultures.
To create my own cultures I copied and pasted the base “0_cultures.txt” and renamed it to “anb_cultures.txt” which makes it seperate from the vanilla ones when the game is loaded. This also means that those existing vanilla cultures are still there in my mod but of course they eventually wont be used, the only reason I chose to keep the “0_cultures.txt” instead of overwriting it is to prevent any dependency issues (for example, X event refers to French cultures – what happens if I use the event but french cultures dont exist?)
At its core the cultures.txt file is comprised of:
-a culture group, eg “germanic” or in this case “lencori”
-cultures within that group, eg “austrian” or in this case “high_lorentish”
-dynasty_names within the culture group or culture, which informs what surnames your rulers can have
-male and female names, which does a similar thing as above
Making a Religion
The last thing we need to finish off our showcase is a religion! Again, each province has a religion and each country has a religion (for example France is Catholic, the Ottomans are Sunni Muslim)
As this is a fantasy mod, my main inspiration for the deities was your classic pantheon of gods which were both prominent in real-life such as the Roman, Greek and Norse Gods or in fantasy like the gods of Dungeons & Dragons’ Forgotten Realms. I’ve already worked out a rough idea of the main gods of the cannorian_pantheon so all I need is to put them in game!
Each religion has different mechanics and in our case the most suitable mechanic was the hinduism religion, which makes use of the personal_deity mechanic allowing players to select a new patron god every time they get a new ruler
Again, like the cultures, I didn’t replace the existing “0_religions.txt” but made my own “anb_religions.txt” (anb meaning Anbennar) to keep dependency errors to a minimum
The image to the far left is essentially a copied and pasted version of the hinduism religion but with different names
In addition to that, I need to make my own variant of the personal_deity, like other Paradox modding all you need for this is editing a text file once again. The image to the right shows that off, with the deity castellos and the_dame showing different benefits if you pick them as your patron (eg Castellos grants -1 unrest)
Putting it all together
With that sorted I went through various provinces and created custom variants of my own for the mod, changing the owners and other stats as shown, ending up with this below:
As you can see there’s some custom countries in there like Deranne, the aforementioned Lorent, Redglades and others.
There’s also existing vanilla EU4 countries like Milan and Sweden in there as they hold a small number of provinces, for this demonstration I wanted to focus on big countries to create and show off.
My next plan is to flesh this region out more and add the rest of the countries (so we dont have vanilla ones) as well as changing all the names of the provinces
So this is Week 7 which is usually Feedback Week, but for us its our Progress Presentation so that the class and our lecturers can see how we’re getting on with our projects and give feedback.
-My proposed idea and dissertation (I didn’t pitch as I missed the first month of uni due to my internship so this’ll be the first time most people will hear about my idea)
-Explain what worldbuilding is and my personal context
-The existence of this blog
-The one-pagers from the blog
-EU4 Fantasy Mod idea and context
-Fantasy Mod Vertical Slice
I know making a EU4 Mod is hard, let alone one that turns it into a fantasy world, so to show off that it IS possible, I plan on making a small vertical slice of a region in my game which I’ll cover in the post right after!
However I ended up starting again (honestly I don’t remember why, maybe because the geology was off or I needed to make it more manually?) and ended up with a new map shortly after in 2015. As such the 2017 had had much more polish to it and much more stuff besides the files needed for EU4 (such as locations of cities, etc)
Points of Interest
I’ll be referring to each point of interest annotated on the map from left to right:
-In 2014 this was a small circle at the center of the Western Continent
-In 2017 I made this the defining piece of the continent, it kind of acts like a the Caribbean but even more encompassing of the region. I also made it look a bit more natural but keen-eye’d players should be able to notice that something’s off with the place: it’s not natural at all.
Large Inland Sea / Cool Narrow Sea
-In 2014 I had this huge vertical inland sea west of the Dameshead, I thought this was really cool as it allowed from a different way to look at the Mediterranean gameplay you see in EU4. This idea also had a very interesting narrow sea to the south of the Dameshead, which would mean ships would have to navigate a densely populated sea region to go to the Eastern Continent
-In 2017 both of these is no more, instead I have a more traditional Mediterranean region and your typical West African coast to navigate around. Honestly this is the only thing I would change with the map, I felt that the vertical inland sea would have brought a lot more new things to the plate but any attempts to add it didn’t really work out. Instead I have a Cool Lakes region which is a reimagining of “What if the Canadian Great Lakes were more populated and connected to the sea?”
-In 2014 the Dameshead was a coincidence and decided to roll with it as it seemed like a cool geographical phenomenon. Plus it adds a kind of central sea-hub region for the game, worldbuilding-wise the Dameshead becomes a very important trade center and pretty much the center of civilization for much of history. It pretty much also inspired one of the main gods of the setting: The Dame.
-In 2017 I kept the Dameshead as a defining piece of the land but rotated it west. Within my story the elves came from the western continent so I thought it’d be symbolic that the main feature of their new land is a head looking west to their home.
-In 2014 I created a place that would serve as an isolated realm, surrounded by mountains and inhopsitable swamps. I was quite into Gothic Horror and I played a lot of the Ravenloft setting in Neverwinter Nights back then
-In 2017 it’s still there but I moved it to a move centralized location, as Eastern Europe was in the past, and a gateway between east and west. The marsh swampland now encompasses most of the region and serves as a brutal and deadly battleground
-You cant have a fantasy setting without dwarves right?! In 2014 I created a large mountainous region up north where you could have gameplay of mountain interiors and dwarven holds – this was really cool and different but my only issue was that it was relatively isolated and players wouldn’t interact with anyone at all
-In 2017 I opted out of the large internal mountain region and just created a huge continent-spanning mountain range (The Serpentspine Mountains), I felt that I could still do the internal mountain hold provinces but on a smaller scale – but at least in this version dwarven players get a lot of exposure to other nations
In 2014 I just combined them both into one region, but it due to the split nature of the southern continents it the area overall felt really small and isolated – in both old and new maps this region will be inhabited by the sun elves after their arrival from the west.
In 2017 I split the region into two instead, with a larger desert area connecting the both of them – this opened up a lot more opportunities for their histories to intertwine without being the same – also I wanted an Egypt analogue to coexist with their sun elven neighbours in the present day
-In 2014 I wasn’t really thinking of the map as one piece but solely focuses on the central continent (named Cannor) so its much lower
-In 2017 its much higher now and about the middle of the map, so it allows for more variety in environments
-As you can see in 2014 I had done the province map for the main region of Cannor, including the Dwarven Holds in the north
-In 2017, since i’ve only started recently for this honours project, I’ve only done Western Cannor but its much denser than the one before – i’ve also added some sea provinces to surround the provinces i’ve made
So what does the map look like in Photoshop?
I’ve extended my layers file to illustrate how much there is in the Photoshop File, as you can see I have every single map file needed in there and I just export them as different Index’d .bmps – also note other miscellaneous layers more related to worldbuilding such as Places – Cannor (which contain the names on the picture above) and History (which contains general political maps through various periods of time)
As in all strategy games, the map is the very core of the game. This goes the same for Europa Universalis IV and this mod!
As the next few posts relating to the mod development will be map-centric I thought it’d be a good idea to familiarize any readers with making an EU4 map works and what kind of files and maps you actually need.
The core map files
To make the map above you will need at the very minimum a:
-Heightmap and Normal Map
The first steps I took to making the Mod was to create my own version of the above.
So what do these even mean? Well keep reading and i’ll tell you!
Height Map and Normal Map
If you’re familiar with 3D modeling then this is pretty much what you’d expect:
The grayscale Heightmap handles the elevation of the terrain in the 3D in-game map, with whiter shades being higher elevation and darker being lower.
The Normal Map (also known as a bump map) is generated from the Heightmap and accentuates differences in elevation by creating a fake lighting shadow effect
In terms of EU4 and other Paradox games if you have a plain heightmap with the basic gray for land and darker gray for water and no other elevation, you’ll end up with a flat map – which is perfectly fine if you’re looking for the absolute minimum in creating a total conversion mod.
Also, heightmaps need to be in grayscale mode but if you just convert it normally in Photoshop (Image -> Mode -> Grayscale) i’ve found that it makes the image fuzzy and not pixel-perfect. An alternate I found is to do it via Indexing (Image -> Mode -> Indexed Color -> Grayscale).
The Terrain Map affects the game both mechanically and visually:
-Mechanically, it determines which terrain type each province is (for example a province in the desert will have the ‘desert’ terrain in-game which will effect how prosperous the province is or how many soldiers can fight on it at once or how quick armies can move across it)
-Visually, whatever terrain type you put on this map also shows up in-game – if you place the desert terrain on the map, then it’ll look like a desert in-game
Like other maps used in EU4 the Terrain Map uses Indexing, in which the file is restricted to a specific RGB colour palette which translates to something in-game, if you don’t index your map properly (or use the wrong index) then any attempts in loading the game will crash. Remembering to index your files is an early lesson any modder using Paradox’s Clausewitz Engine will learn.
An example of the colour index in the Terrain Map is Desert (206 169 99), Plains (86 124 27) and Hills (0 86 6).
You could potentially add more terrains by editing the terrain.txt but I given my setting is set in a world where geology and earth sciences are pretty much the same, I don’t really need to!
Much like the Terrain Map before, the Rivers Map also has its own colour Index and also informs the engine both mechanically and visually:
-Mechanically any province that has a river flowing through it will get a River Crossing Penalty modifier, which effects rolls in combat (covered in Honours Blog #8)
-Visually: there’s rivers of the map!
As for the colour index there are several types of blue which indicate the size and width of the river, the darker the blue the stronger and wider the river. There are also other colours such as Red, Green and Yellow which handle where the rivers join together, where rivers start, and where rivers diverge in deltas, respectively.
Another thing of note is that all rivers must be 1-Pixel-Thick, so if you have a bit of your river thats accidentally got 2-pixels then it wont show up! Paradox map modding is all about being pixel-perfect!
Worldbuilding Rivers 101
In terms of worldbuilding, one thing learned from /r/worldbuilding is rivers actually work:
-Rivers don’t diverge, they converge – meaning Rivers dont split, they join!
-Rivers flow from the highlands to the lowlands and always follow the path of least resistance – the end of rivers will always be one exit (Delta’s like the Nile is an exception!)
-Rivers don’t link two oceans together, aka you cant have a river that goes from the the north of France at the English Channel all the day to the south of France and link to the Mediterranean – this is because its not really a river anymore, you just made a really narrow ocean and split France into two islands!
-Rivers are like trees, at the mouth of it you have a large trunk which leads to the ocean and as you go up you go to branches then to twigs
This might be simple enough when you read it, but a lot of novice worldbuilders who don’t look into these kind of things make this mistake all the time!
Same thing as last time, the Trees Map has indexes which indicate the types of trees we have: in general the green trees are temperate forests and the blueish-green are the coniferous huge pine trees we see in places like Canada and Russia.
For some reason the Trees Map is of a different size and resolution than the other maps which causes a bit of an issue in making trees appear exactly where you want them, eventually I realised that I could simply resize my own trees map to the size used here and work on it from there.
Design change relating to trees and terrain placement
Players were often confused whether a province had this terrain or that terrain, or if they were forested or not so Paradox has recently changed their design ethos surrounding both trees as well as terrain:
-Instead of trees and terrain overlapping into several provinces like real life, trees and terrain will be influenced by the actual province shape itself.
-This means that Marshland provinces will clearly have majority or the entirety of its shape filled with Marshland terrain, and this also goes to Forest province – which will be entirely covered in trees.
While this does go against the believably and realism, it does help the player discern better what they are getting into with a glance instead of having to properly click the province and examine its terrain type
This of course will influence my worldbuilding and development of the map (aha! a link to the dissertation!)
-Essentially, the bounds of forests and terrain will be influenced by the shape of the province I make or vice versa, depending on where I had previously said “This place will have a forest, or this place will have a marsh” the shape of the provinces I draw will have to conform mostly to that idea
The Color Map is purely aesthetic and adds the detail you want in your map. The Terrain Map alone only does the minimal and just tiles the same terrain type over and over again so the Color Map helps hide that and makes this look more natural.
I’m still not sure how I’ll do this yet (as my map is made-up, after all!) but this will be something I tackle later on as it’s not really needed to get the mod up-and-running.
The bread-and-butter of all Paradox strategy games.
The Province Map does not conform to Index colours like the ones before but it does care greatly about RGB values:
-Each province has a unique RGB that is used to refer to it
-This links to the definitions file which has every single province in their game, their Province ID and what RGB value that ID is associated with
In terms of development I was conflicted on how to handle this, I had to make my own province map but I didn’t know how to go about it: I was either going to:
-Create my own custom definitions file and make up RGB colours as I go
-or just use the same colours as the existing one, and just edit the province.txt files later
In the end I decided to go with the latter, as it allowed me to fill out provinces faster as I just had to colour pick, paint and go to the next colour
This would mean that when I start up my mod and have the existing province RGB’s used, the provinces will correlate to the EU4 provinces (eg i’ll have a Paris province in my mod). This can be fixed by editing its specific province.txt file (which we’ll cover in the next next EU4 Mod post)
Thanks to a handly little Province ID map I was guided to (here), I overlayed that ontop of the basic province map so I know which colours go with which ID:
Black areas are province i’ve already used in my own Province Map
The process goes like this:
-Find the next ID along and what color it is
-Use Color Picker tool to get the color
-Fill in the used province with Black
-Go to my Province Map and draw a new province
-Rinse and Repeat
A problem I’ll face later on is not knowing what ID my provinces are when I go about changing their names and statistics, but I can just bring back the default Province Map (without any black filled in areas) and try to compare colors and IDs from there or more likely I can get rid of the province name localisation files which will turn each province’s name in game to something like this: PROV1, PROV2, PROV300, etc
While we’re on the topic of introductions, I thought it’d be best to give any readers a quick rundown of Europa Universalis IV (shortened down to EU4), the game that i’ll be making my Fantasy Mod for!
Europa Universalis IV (released in 2013) is the fourth installment of the Europa Universalis series by Paradox Interactive, a Swedish developer/publisher known for their Grand Strategy games. Other recent notable Paradox games include the medieval dynasty simulator Crusader Kings II (2012), the World War II strategy game Hearts of Iron IV (2016) and the sci-fi 4X game Stellaris (2016). Paradox has also published many notable games such as Mount & Blade (2008), the Magicka series, Sim City successor Cities: Skylines (2015) and Obsidian Entertainment’s recent RPGs Pillars of Eternity (2015) and Tyranny (2016).
Paradox focuses more on the niche and hardcore genres which all started with the first Europa Universalis all the way back in 2000. However they have recently taken a step back on the hardcore aspect and tried to make their games easier to understand and accessible, putting accessibility on the forefront and part of their core game pillars.
This was seen first in Europa Universalis IV which was its predecessor in a new graphical coat, less byzantine systems, less micromanagement, more quality of life mechanics and more intuitive UI. The real star in the Accessibility pillar came in the form of Stellaris which sold 200,000 copies, becoming Paradox’s fastest-selling game ever.
Paradox follows the Long Tail Business Model, which basically means that their main line of games have a very long shelf life: its games as a paltform This is done via constant patches as well as multiple DLCs every year that come with a slew of free content for everyone.
In addition to continued support for their games, Paradox is also very mod-friendly, with their entire system easily edited with Photoshop and Text Editor alone. They also have their own Usermod Coordinator which helps push and deliver features that will help the modding community in the long run. This very open support for modding alone increases their games’ longevity even more. A good example of this was Crusader Kings II’s Game of Thrones mod, which gained a lot of publicity from the press at the time, and which was what persuaded me to buy the game and enter Paradox’s sphere of games for the very first time.
EU4 In Brief
Europa Universalis IV is a grand-strategy game encompassing the entire world, where you can play as any nation from the years 1444-1821. After selecting your country you will control them throughout several periods of history, and witness events both specific to your country but also to your age such as the Renaissance, the Age of Exploration and Colonization of the Americas, the Protestant Reformation to the Revolutions of the 1700s and the Age of Imperialism shortly after. The game itself becomes a sandbox when you hit play: its not a guarantee that Spain will colonize most of South America or if Britain will even turn Protestant, or if France will even undergo a Revolution – there are some events that may guide countries to slightly follow their historical trajectory but that’s pretty much it.
So a very popular strategy game out there is Civillization, so when talking about EU4 it can be easier to just compare and contrast:
Simple and intuitive
Very complex, a lot of things to keep track of
Randomized Map, flat start: everyone starts the same
World Map, everyone starts differently (one country is huge, another is small)
Who you can play
Selected Civillizations (eg Germany)
Any country in the timeframe (eg the Duchy of Austria, or the city of Hamburg instead of ‘Germany’)
Flow of Play
4X (Explore, Expand, Exploit, Exterminate – you go through this linearly and you’re done)
Realtime (but you can pause whenever you want!)
Grand Strategy (There is no linear process of flow, there’s no overall goal, its sandbox)
Scope of Management
City-based, its all about building and expanding your borders
Empire/country-based, its all about managing your empire both in and out
Very simple, pretty much declare war or denounce – once you war you dont stop until they are wiped out
Only a few major nations and the rest are small city-states, diplomacy is mostly competing with the major nations
Very complex, must have a valid reason to declare war and being a warmonger will cause a coalition to shut you down (not wipe you out the map but make you lose a lot of provinces)
A lot more independent nations with their own agendas means a lot more diplomacy overall (eg having an intricate web of alliances that makes WWI blush)
Tactical, a lot of units with different abilities
Simplified, just two 3D models representing armies fighting – usually the one with the higher numbers (aka troops) wins
Very detailed branching tree from the dawn of civillization to now
Linear progression, technology unlocks new buildings, interactions or adds new modifiers (eg your Trade Range is increased by 10.0)
Sense of Space
A lot of empty space waiting to be colonised, making new cities is up to the players
Every space is filled and inhabited by their own players. The Americas can be colonised similarly to Civ but is also filled with native countries you can play or fight against
Sense of Scale
Small. Cities represent a very large region that would be inhabited by many other cities in real life
You will encounter every other nation in the game in your playthrough (eg to get a Domination Victory you need to control everyone’s capital)
Large. Provinces are the capturable city aspect of civ – cities are irrelevant
You will not encounter every other nation in the game in your playthrough
In short, Civ is all about empire-building and dealing with external conflicts.
Europa Universalis is all about empire-management, dealing with external conflicts is just one of the many things you can do.
In EU4 your situation vastly differs not only due to abilities but depending on who you play and where you are:
-as France you are competing with a lot of powers like Spain, England and the Holy Roman Empire (all those little states that make up Germany): will you fight and push your way inland? Will you colonise America and compete for naval domination?
Your game will be full of huge continent-spanning wars with the biggest and largest powers around
-as Austria you are right in the edge of the Holy Roman Empire, everyone to the north and west of you is part of the Empire like yourself – will you carve your way into Germany to unite the Empire knowing you’ll make a lot of enemies? Will you go east to and fight Poland and Russia? What about the Ottoman Muslims to the south, will you take on the mantle of the Christian protector of Europe?
Your game will involve a lot of diplomacy and fighting on different fronts
-as Muscovy you are landlocked: the ocean is not an option to you like France or Spain. Everyone around you are Nomadic Muslim hordes and descendants of Genghis Khan
Your gameplay will revolve around uniting all of Russia and fighting back the hordes of the east, only then will Western Europe know your wrath.
-what if you’re Genoa? You’re a very small Italian city-state surrounded by a lot of big neighbours. You’re small so you’ll need to play it safe and build a lot of allies before you expand. What if France invades, maybe you should make friends with him instead? But what if Austria invades then, maybe he’s a better ally? What about the seas, can you make money and grow your power there instead?
Your game will be one of patience and opportunity, befriend bigger countries and dominate the seas
Countries and Diplomacy
Each country has a ruler which their own stats (which we’ll cover in Technologies and Ideas) and depending on the government type an heir and a consort (Republics of course don’t get heirs and consorts as they are an elective position but Monarchies do).
Each country also has its own religion, government type and types of cultures it accepts (more on that in Provinces)
Interacting with countries is done through the Diplomacy Screen, where several options can be chosen such as Improving Relations which makes the country like you better, sending money, asking for permission for your armies to walk across their lands or simply declaring war.
Every country has their own wants and desires, as well as opinions on other countries. This will affect their attitudes to the specific country, for example because England desires a lot of your provinces you aren’t going to be friends any time soon.
Technologies and Ideas
Improving your country can be done in two ways: increasing technology or obtaining ideas.
Technology is linear in EU4 so everyone researches the same thing but not everyone will be on the same level.How often you can improve your tech is determined primarily by your ruler’s stats. Each ruler has a stat in Administration, Diplomacy and Military which builds up every month (known as Monarch Power). For example: A ruler with 2 Administration will generate 2 Administrative Power per month.
Another way to spend your Monarch Power is via Ideas.Each country has their own unique set of ideas (seen in the top row of ideas right below French Ideas) as well as generic idea slots they can unlock. You must spend the respective Monarch Power (so the Swords means Military so you spend Military Power for Defensive Ideas) to move onto the next bonus of the idea slot (so here the player has unlocked Military Drill but must spend more points to get the next ability along). Unlocking generic ideas will build up progress to unlocking your country’s unique set of ideas.
As you can see France has completed all Economic, Offensive and Exploration ideas and because of that they’ve unlocked all their own French Ideas. However they are halfway through the Defensive Ideas
Provinces and Trade
All of Paradox’s games (bar Stellaris) is built up on a foundation of Provinces. Provinces make up a country but each province has its own little stats attached:
So here is the province screen for Paris. Each province has (from the left):
-A type of terrain (so Paris has Farmlands as seen in the large picture at the top)
-Economic stats (Tax and Production)
-Cores & Claims (who the rightful owner is, so if someone takes Paris France will still have it as a core province and will be able to fight for it back without any extra hassle)
-Culture (so Paris is of the Francien culture, if a non-Francien accepting culture for example the English take over, Paris is more likely to have Unrest)
-Religion (same as above)
-Buildings (so to the right we see Paris has a level 4 Fortification)
-Trade Goods (near where it says Champagne there’s an image of red cloth, Paris produces Cloth with determines the Production output)
-Trade Power (dictates the strength of keeping Trade Goods and Production local, more below)
This Trade Map is a new addition to EU4 and simulates the flow of goods around the world, for this example we’ll be talking about the Champagne and English Channel areas (Red and Orange).
If we look to Champagne there is a large red box with the number 8.0 and a coin symbol: this shows us the Trade Value in the Champagne region.
We will also see smaller boxes with other numbers in as well as lines with arrows. These show the flow of trade. So for example the 5.61 lies (not very clearly!) on an arrow leading to the English Channel trade area: this means 5.61 worth of gold is being pushed forward into the English Channel from Champagne. The little Netherlands flag below it shows us who’s responsible of pushing it forward – this is probably because the Netherlands has some provinces in Champagne that have enough Trade Power (mentioned before) to push it to their desired direction.
Earning Trade Value depends on the Trade Power in the area. Above we can see the English Channel area in which England has 38% of Trade Power, meaning they will earn 38% of the 18.9 gold up for grabs there.
But why is this system good?
-Because it allows another way to grow your nation. A country like Venice may be small but they may have special modifiers or strong provinces that can allow them to push the trade in the Mediterranean back to an area where they are strongest
-Because it makes colonization interesting: see all that line coming from the left? That’s from North America. You may want to keep colonising there (inhabiting provinces and thus creating trade value) only to push it back to your home port and profit!
How warfare works is pretty simple:
-You move an army to besiege a province, every month there’s a percentage chance to capture it and if you fail it increases. Eventually the province will be captured and your army can move on
-Combat is when two armies meet, the core of it is dice rolling against each other with several stats in mind eg the amount of unitys, the discipline of the army (how much damage the army deals and takes) and their morale (how long they can withstand damage) – the first army to break Morale loses the battle and flees, with losses taken via discipline taken off how many units they have left
Winning wars is done by War Score (the percentage on the bottom right of the screenshot with the English flag). Gaining War Score is done by capturing provinces and winning battles.
The more War Score you have the more you can take from a war, so in the example above you’d need 10% Warscore for England to agree to cede Alencon.
You can also ask for other things aside from provinces such as annuling their alliance treaties, releasing smaller nations within their country, war reperations over time or just cold hard cash.
You can never ask for more than a 100% worth of stuff so you won’t be able to wipe out large countries in one go, you also have to make sure you aren’t being too much of a warmonger. Constantly warring and taking provinces builds of your Aggressive Expansion stat, and if that goes to high many countries will rally against you in a coalition (lets just say Napoleon had a very high Aggressive Expansion that made everyone in Europe coalition against him… several times)
That was quite long wasn’t it?
If you’re interested, quill18 does a much better job in explaining it all in his series here.