This article is considered accurate for the current version of the game.
Colonization is one of the gameplay features available within the game as the setting is within the age of colonization. Nations can explore and colonize the continents of the Americas, Asia, and Africa.
The essential aim of colonialism is to generally out-perform your rivals, through:
- Prestige and influence: To mold a prestigious global empire, befitting of your great nation; and
- Trade and finance: To maintain dominance and control of global trade by cultivating and steering trade towards your capital
You should accept that tax and tariffs from your colonies will make up the minority of your profits.
 AI colonizers
Not all AI nations will gain colonists, and only a limited number of nations will join the colonial race. An AI nation may gain a colonist via their national ideas or unlocking exploration ideas or expansion ideas.
- Castile, USA, Norway, Russia and Malayan nations can gain colonists from their national ideas.
- Portugal, Castile, England, Scotland, Ireland, Brittany, Granada, France, Netherlands, Aragon and Burgundy can get colonists from exploration ideas.
- Portugal, Castile, Russia and Japan can get colonists from expansion ideas.
Although some uncolonized provinces may be visible at the beginning of the game, much of both land and water is covered by terra incognita. Discovering these areas is useful for finding provinces to colonize.
- An army led by a Conquistador can move into terra incognita land provinces and thus discover them. If that land is owned by another country, the Conquistador will discover the province instead of moving into it. Skilled Conquistadors have a chance to discover adjacent provinces as well. Armies without conquistadors can march into land provinces owned by enemies if at war.
- A fleet led by an Explorer can move into terra incognita sea provinces and thus discover them. Upon entering a sea province they also have a chance to discover neighboring coastal provinces (increased by explorer skill).
- Undiscovered land provinces have a chance per month to be discovered by owners of adjacent provinces (typically taking 3–5 years). Russia has an idea that makes this discovery instant.
- Eventually (how long)? discoveries will spread to other countries of the same tech group (?). A country that changes tech group will immediately have all provinces known to that tech group revealed.
Whilst historically the first circumnavigation of the globe of 1519-21 by the Spanish was considered major achievement, EU4 does not reward players for completing the journey.
Circumnavigation is however a challenging and rewarding task, especially in the early stages of the game, where naval attrition and relatively delicate ship designs from primitive diplomatic technology makes voyages a life and death game. However, with patience and planning, you can successfully guide your explorer's expeditionary fleet around the world without turning back.
- Only use light ships in your expeditionary fleet, for their navigational speed, meaning you can get around to more provinces before the attritional effects of a long journey can set in.
- Fleet basing rights are crucial in the game, as in reality. As in Magellan's circumnavigation, you will need to stop at regular intervals to rest your crews, repair your ships and restock your cargo holds. This is simulated by gaining access to foreign ports. This can be tricky, as generally speaking far-flung lands will look down upon your different religion (Different religions group: -10 opinion). This can generally be overcome by setting a rival of the country as your rival (enemy of my enemy: +20 opinion), allowing you to send a diplomat to ask for fleet basing.
- NB: Don't forget to also cancel fleet basing once it is no longer useful, as fleet basing monthly fees can add up, especially early game when your income may not be very large.
- Diplomatic constraints will be your main limitation with this tactic: namely, you will only have two or three diplomats in the early game. The further your envoys jet around the world to secure fleet basing rights for you, the longer they will take to return each time. This problem can mean it takes over half a year for a diplomat to return from a country for re-assignment. Solution? Be smart in your choice of fleet basing. Rather than the OPM on the west of India, choose the sprawling island-chain empire in the east. This will give you more ports to choose from.
- Keep to the coast and you'll reduce the time you find yourself spending in port to repair as you explore new nooks of ocean.
- Explore; return and repair; rinse and repeat. Consider this strategy. Exploring new sea provinces takes much longer than traversing explored ones, meaning that mining away at new parts of the map in small portions, returning to port and then continuing on a small bit will mean success.
- Don't take risks with your precious explorer. If your over-ambitious exploration fleet makes the mistake of trying to explore that 'one more sea province...' in the middle of the Pacific, there is a good chance your ships will sink from attritional damage, killing your crew and prized explorer in the process.
- Tag-team fleets are a good strategy for exploring the expanses of the Pacific (and elsewhere). Send HMS Nonsuch with your explorer to Sea Province Group X. Return to port, leave HMS Nonsuch to repair while your explorer hops onto HMS Howmuch to travel to Sea Province Group X and continue on to explore group Y. Rinse and repeat. This way, your explorer is always being kept busy, which is important due to the mortal nature of military leaders.
Using these tactics, you should be able to get around the world from the moment you recruit your first explorer. There are benefits to circumnavigation:
- Events, decisions and missions: Some game mechanics require a knowledge of a country's or region's existence, which can only be achieved by extensive exploration nearing circumnavigation.
- Colonization & Merchant scouting: Circumnavigation will give you opportunities to scout out strategic points of interest for future colonization & trade efforts.
A colonist is required to start a colony.
- Colonial Ventures and Free Colonies ideas in Exploration idea group gives 1 colonist each.
- Additional Colonists idea in Expansion idea group gives another colonist.
- There are also 3 unique national ideas which gives a bonus colonist each - Castile, Russia and Norway. Malayan ideas also give a colonist.
The range where you can establish a colony from the core province of your own nation or from a foreign nation which you have a fleet basing rights agreement is called the colonial range. It expands depending on your diplomatic technology level, modifiers and other bonuses.
 Travel time
The speed in which your colonists travel to claim and establish colonial territory, it is primarily modified by distance from your capital.
Once a colonist arrives in an unowned province the population starts at 10. Colony populations grow at a base rate of 50 per year, on full colonial maintenance. In addition, as long as a colonist remains in a colony, they have a chance each month of bringing in 30 additional population, speeding growth greatly. A colony becomes a full city when its population reaches 1000, and is destroyed if its population reaches 0.
|Modifier||Colonists per year|
|Colonial maintenance||-50 to +50|
|Land of Opportunity idea (Exploration Ideas 4)||+33|
|Colonial Expansion decision||+5|
|Colonial Restrictions decision||-10|
|Tropical, Arctic, or Arid||-10|
 Colonist chance
Each 1% chance for a colonist to bring in additional settlers will bring in 3.6 settlers per year on average.
The chance is determined by the following:
|Base + Base Value||10%||36|
|Per 100 population ("colony level")||4%||14.4|
|Per 100% Production Efficiency||20%||72|
|Per native aggressiveness||-0.5%||-1.8|
|Trading in Cotton||5%||18|
|Same culture group||1%||3.6|
|Tropical, Arctic, or Arid||-10%||-36|
|Colonial Restrictions decision||-10%||-36|
|Benign Neglect decision||5%||18|
 Colonial Enthusiasm
There is a modifier called 'Colonial Enthusiasm' which can be given through events and missions. The event 'Colonist Rush', from Exploration, and 'Colonist Enthusiasm', from Expansion give this modifier. These two events can only happen if the player has picked the associated idea group. The following bonuses are given:
The modifier lasts for 5 years.
Colonial maintenance is the money that you spend in maintaining your colonies. At 100% maintenance, the base cost of a colony per year is given by
base cost per year = 24 + base tax / 2
A country can support a number of colonies equal to its number of colonists at the base maintenance cost. After this the marginal maintenance cost starts rising quadratically:
maintenance cost multiplier for nth colony = max(n - number of colonists, 1)^2
Note that unlike force limit, this is applied to each colony individually in the order that they were founded, so the more recent colonies will be saddled with the higher cost multipliers.
Colonizable provinces are usually occupied by natives, who may attack a colony there. If no land units are stationed there, they will reduce the colony's population. If land units are stationed there they will fight them. Natives are also very likely to attack land units passing through their province.
The size of the native population determines how many native regiments attack at a time. The native population can be reduced using the Attack Natives military action. However, when the colony becomes a full city it will gain 0.2 base tax and 0.1 base kManpower per 1000 remaining native population, so it is usually beneficial to leave the native population alone.
Aggressiveness ranges from 0 to 10. It determines how likely the natives are to attack. (How much per point?)
Ferocity ranges from 0 to 10. Natives get a +5% damage bonus per point of Ferocity.
 Colonial provinces
 Province attributes
- A colonial province is assigned the culture and religion of its owner when a colonist arrives there.
- A colonial province is assigned a trade good sometime after it reaches 300 population.
- It costs only 20% of the normal cost for a country to core its colony.
 Distant overseas
Colonies are often "distant overseas", which means neither of the following is true:
- The province is on the same continent as the capital.
- The province has a land connection to the capital (including crossable straits).
Distant overseas has the following effects:
- Tax modifier: -90%
- No production income.
- Colonies instead generate tariffs equal to 20% of the (production income they would have produced + base tax). The exception is provinces that produce Gold, which give full production income even when distant overseas.
- Each distant overseas province requires 1 ship on patrol to produce income at full efficiency.
- Manpower modifier: -50%
- Local land force limit: x1/5
- Local naval force limit: x1/6
 Fleet basing rights
If you want to colonize early on the game without colonizing unnecessary provinces and producing enough gold to cover the expenses of an agreement, it is possible to colonize directly on the important unoccupied provinces by signing a fleet basing rights agreement with your European neighbors or with other nations near the unoccupied province. If you cannot sustain the monthly cost of the agreement, it is possible to cancel the agreement right away after you start the process of coring the province, but take note that it will prevent you from colonizing and coring other unoccupied provinces nearby unless your colony becomes one of your core provinces.
How to get fleet basing rights
The country's chance of granting fleet basing rights does depend on diplomatic opinion in the same way as other actions - the rate seems to be lower. So the "Improve relations" action does help to get this agreement, but it takes longer than with usual relations-based actions. Ruler and country's "Diplomatic skill" is what determines it.
- Colonial Expansion vs. Colonial Restrictions: The bonus from Colonial Expansion is very small, but might as well be taken if one is not planning to eventually take Colonial Restrictions. At an effective -41.68 colonists per year per colony on average, Colonial Restrictions is a rather severe damper on colonial growth, but could be taken after all desired colonies are taken, assuming one is not also aiming for Economic Ideas.
 Island hopping
At lower levels of Diplomatic technology, when colonization range is still short, island hopping is essential to crossing oceans. Here are some major paths:
 Atlantic Ocean
Listed roughly from north to south then east to west:
- In the earliest start, Norway controls a few islands to the north of the British Isles. From east to west these are the Shetlands, Färöarna, and most importantly, Iceland. From Iceland the nearest land to the west is Greenland, from which the east coast of modern-day Canada is easily reached.
- Northwest of Africa, Portugal controls Madeira and the Azores, while the Canarias (next to Madeira) belong to Castille and later Spain. These give a boost in getting to Bermuda, the easternmost of the Caribbean islands, or the northeast coast of South America.
- Cape Verde is initially unowned, but eventually belongs to Portugal. It is the closest approach to the New World from Europe or Africa, being situated roughly between the closest parts of Africa and South America.
- To the very south there is St. Helena, initially unowned. This gives a slight boost towards the east coast of South America or the Falkland Islands. This is a rather far choice, however.
 Pacific Ocean
Listed roughly from north to south then west to east:
- The islands north of Japan and the Kamchatka Peninsula will lead to Aleut, which is connected to the North American mainland. This is the shortest path.
- Guam from the north or Palau from the west will lead to Micronesia. From there, the Marshall Islands are next to the east, then Wake Island to the north, then Midway to the east, and finally Hawaii to the east. However, it is a long way from Hawaii to the North American mainland.
- Numerous islands to the east of Australia lead to the Samoa Islands. From there, the Society Islands, Tahiti, and Rapanui give further reach east. From the last, the west coast of South America (much of it occupied by the Inca) can be reached, or the Galápagos to the northeast.
Most habitable land in Australia is on the east coast. Listed roughly from north to south:
- The safest route is to go to Micronesia or the Marshall Islands as above, then south to Nauru, Vanuatu, and New Caledonia; this also provides the closest point to New Zealand.
- A shorter route is to hug the north coast of New Guinea more closely: Irian, Rabaul and/or Papua, and the Solomon Islands. However, this route has severe native activity.
- Australia can also be rounded from the south. Starting from any of the islands northwest of Australia, Wadjuk on the southwest corner of Australia can be colonized. From there it's straight to Kaurna on the east side of the continent.
 Indian Ocean
Listed from east to west:
- The Andamans (unowned) form an outpost in the Bay of Bengal between modern-day India and the Malay Archipelago. All of the surrounding land is owned, however.
- South of the Malay Archipelago is unowned Christmas Island, followed by Cocos island to the west. To the west of that is Diego Garcia, right in the middle of the Indian Ocean.
- North of Diego Garcia are the Maldives and Ceylon, leading to the south tip of modern-day India.
- West of Diego Garcia are Mahe slightly to the north, and Mauritus and Bourbon to the south. West of these is Madagascar.