殖民是将无主地转化为殖民地的过程。它可以为任何希望成为列强的国家提供一些重要的好处：
《黑暗之心》中的殖民
在《黑暗之心》扩展包中，殖民是一项颇为复杂的内容。为了增长成为殖民帝国的潜力，你的国家需要一支强大的海军和正确的科技，使得你能够扩张到那些不适宜居住的地区。
机制
殖民分为三个步骤。
探险
要殖民一个省份，该省份必须在你的国家所能及的范围内，并达到或超过你的国家的最低生活条件。只要目标省份离最近的海军基地足够近，或者与一个已经被控制的省份相邻，目标省份就在殖民范围之内（毗邻一个卫星国也计入）。一个国家的最低生活条件受到其发现的科技的影响。
派遣一支探险队需要消耗100点殖民力量，但如果目标省份毗邻一个已经被控制的省份，则只需要80点。
探险队派出后，必须等待一段时间才能对殖民地作出下一步行动。如果没有其他国家在该地区进行殖民行动，殖民地可以直接变成保护国，只需付出一点点额外的殖民力量成本。然而，如果其他国家加入了竞争，这就变成了一场竞赛，两个国家将不断升级他们的远征队，直到其中一方从竞赛中撤出他们的殖民力量并承认失败。
如果一场殖民竞赛持续太久，它最终将引发一场危机。要想知道这场竞赛有多接近危机，请查看地区视图上的彩色进度条。
殖民省份/保护国
当一个列强或次强的远征队没有受到另一个国家的竞争（可能是因为所有其他竞争对手都退出了），或者当一个国家比最近的竞争对手多投资了三个等级的远征队时，就可以建立保护国。
殖民地的维持成本比保护国高，但它们为国家提供了更多的税收，并且国家可以从中征召军队。然而，工厂不能在殖民地建造。
当一个开化国家通过“索要租借地”或“建立保护国”（尽管名称如此，后者实际上创造了殖民地）的宣战理由从未开化国家征服了一个地区时，也会产生殖民地。注意，即使目标地区已经是获得它的国家的核心，它仍然会变成殖民地而不是本土（这种情况很少见，比如
South Africa收复他们在
Zulu的核心时）。
开化国家可以通过“阳光下的土地”的宣战理由从另一个国家夺取殖民地。
State
To convert a colony to a full-fledged state requires the colony to have a population of at least 1% 
Bureaucrats of accepted culture. This conversion costs colonial points.
Colonial Power
Colonial Power is given by:
- +100 from the technology Post-Nelsonian Thought (listed as "From Improved Technology"). This serves as a base for all Secondary / Great Powers.
- +30 for each naval base built in a core province
- +20 for each additional level on a naval base in a core province
- Combat ships in the nation's navy (if the naval supply limit is exceeded additional ships will lower colonial power):
| Class | Colonial Power |
Supply Weight |
Power per Supply |
|---|---|---|---|
| Frigate | 2 | 1 | 2 |
| Man'o'war | 5 | 2 | 2.5 |
| Commerce Raider | 8 | 3 | 2.6 |
| Ironclad | 12 | 3 | 4 |
| Monitor | 10 | 3 | 3.3 |
| Cruiser | 16 | 20 | 0.8 |
| Battleship | 15 | 50 | 0.3 |
| Dreadnought | 22 | 60 | 0.36 |
Frigates, Man'o'Wars and Commerce Raiders can be used to gain colonial power in the early game, but should be replaced by more efficient Ironclads or Monitors as soon as the latter are available. Ironclads are the most efficient ship class with four colonial power per supply point. However, they are expensive to build, take a long time to finish, and can't be constructed overseas. Thus they are only viable for countries which have many non-overseas naval bases and high preparation time. Countries with few home naval bases or little time to prepare should focus on building Monitors instead. Cruisers, Battleships and Dreadnoughts become available much too late to affect the colonial race and are also by far the least efficient ships.
Colonial Power is invested in colonial races and in making protectorates colonies. If a nation has enough colonial power free, and a colony meets the accepted culture bureaucrat requirement to be made a state, they can incorporate the colony into their nation. This will free up additional colonial power, allowing them to develop new colonies.
The required free colonial power to integrate a colony increases with distance, though, and can easily outstrip the potential colonial power of even a great empire. If a nation wishes to colonize more land, they can release a contiguous group of colonies as a dominion. This is done from the Release tab on the Politics screen, the same way states released as satellites.
Life Rating and Technology
A nation begins the game with a minimum life rating of 35. Though there are a few areas that can be colonized so early, most potential colonies are not so hospitable.
Three inventions can decrease a nation's minimum life rating. They are:
- Prophylaxis against Malaria, from Medicine (Industry / Chemistry and Electricity)
- Mission to Civilize, from State & Government (Culture / Political Thought)
- Colonial Negotiations, from Breech-Loaded Rifles (Army / Light Armament)
Prophylaxis against Malaria has a 2% chance of being discovered by a nation that has learned Medicine, and reduces the minimum life rating by 5.
Mission to Civilize and Colonial Negotiations are more complicated inventions: they have no base discovery chance on their own, but gain a 10% discovery rate both when a great power or a neighbor invent them, and 25% discovery rates when the nation discovers technologies from later decades. Specifically, Mission to Civilize requires techs from 1850:
- Nationalism & Imperialism (Culture / Political Thought)
- Market Regulations (Commerce / Market Functionality)
- Naval Statistics (Navy / Naval Science)
And Colonial Negotiations requires techs from 1870:
- Machine Guns (Army / Light Armament)
- Economic Responsibility (Commerce / Market Functionality)
- Naval Logistics (Navy / Naval Science)
The bonus from discovering any one of the later-era technologies outweighs the combined bonus from a great power and a neighboring power already having the technology.
Generally, if the player is the first to get Colonial Negotiations, and thus able to colonize, the rest of the major powers will quickly (if not immediately) follow suit due to the neighbor bonus. This causes a rush of colonization in the 1870s, especially in Africa where most empty provinces have life rating 10 or 15. (Historically, the Scramble for Africa began in 1881.) Any country who hasn't researched Breech-Loaded Rifles by 1880 will probably miss the boat and find all of Africa already colonized.
Strategy
Early colonization (before 1870)
A handful of provinces have life rating 35 and so their states can be colonized in 1836:
- Alberta and British Columbia: Occasionally the
USA grabs the parts of BC that the 
United Kingdom doesn't already have, but otherwise only the United Kingdom is in a position to colonize them, and almost always does so. - Oklahoma, Colorado, Oregon and Washington: These are contested between the USA and
Mexico. They often go to war over them (when the USA takes the "Manifest Destiny" decision giving them cores on all of the continental US), and the USA usually wins. - Sakhalin: An island north of
Japan. Both 
Russia and Japan have cores, but Japan starts uncivilized and so can't colonize for at least a couple of decades, leaving Russia free to grab it after building a Pacific naval base. - Turkmenia: Initially inaccessible to any power, Russia can colonize by conquering Khivan Uzbekia; the Ottomans would have to conquer two states from Persia.
- Bornu: Being in the interior of west Africa, colonizing this requires conquering part of
Sokoto. This is a strategically important location that can give the player a big advantage during later colonization. - Lourenço Marques, Zambezia (not to be confused with Zambezi) and Mocambique (sic): Inaccessible to anyone but Portugal, they will start colonizing these from day 1.
- South Madagascar:
Portugal and 
France can try for Comoros and Mayotte (despite the state name these islands are north of Madagascar), and the United Kingdom can build a naval base in the Seychelles or Mauritius; anyone else probably won't have range.
A few more have life rating 30 and can be colonized with only Prophylaxis against Malaria. With luck, a quickly westernizing uncivilized country may be able to take some of these, but they are still mostly restricted to an exclusive club.
- Manitoba and Saskatchewan: Only the United Kingdom has access here, unless the USA manages to seize BC.
- Alor, Sunda Islands: Bordering the Netherlands' and Portugal's colonial possessions in Indonesia, this can also be picked up by
Spain. The United Kingdom will have to build a naval base first. - Darfur: Even the AI will conquer Dongola from
Egypt to get access to both this and a coastal province for a port. Only Fasher in the south has life rating 30, but this allows colonizing the entire state. - Amhara and Oromia: These states border (and are partially owned by) Ethiopia, who can get them immediately if they somehow become a secondary power in time; anyone else will have to conquer land from Ethiopia.
- South Georgia: Usually taken by the United Kingdom, this island, historically only ever used as a whaling station and never permanently inhabited, can also be taken by
Brazil or 
Argentina if they become a secondary power at the right time. - South Island and North Island, New Zealand: Only the United Kingdom has anywhere near the range to get these.
The following can be colonized from 1850, once the country has Mission to Civilize:
- East Angola and South Angola: More African states that only Portugal will have access to. These are also the only provinces that can be colonized with only Mission to Civilize and without Prophylaxis against Malaria, but you will want Medicine anyway.
- Interior of Australia: In 1836 the United Kingdom has already colonized the entire coast of Australia, so only they get access here.
- Northwest Territories: Part of Canada, only the United Kingdom is likely to have access.
- Etorofu and Shumshu (the Kuril Islands): Like Sakhalin, both Japan and Russia have cores here; unlike Sakhalin, Japan stands a chance of colonizing them if they're quick to westernize and get colonization tech.
The Scramble for Africa (1870s)
All other uncolonized provinces, including almost all of Africa, have life rating 15 or 10 and can only be colonized with both Mission to Civilize and Colonial Negotiations. Since most powers who have researched Breech-Loaded Rifles get Colonial Negotiations at almost the same time, there is a rush of colonization activity soon after any great power has discovered it. Those with life rating 10 also require Prophylaxis against Malaria, but any savvy power will have it anyway. A more in depth guide can be read here: Guide for Scramble of Africa
In the base game and in A House Divided
Mechanics
To colonize an uncolonized area, the following requirements must be met:
- Have a country status of at least secondary power (i.e. civilized and rank 16 or better);
- A naval base in range OR share a land border with the target colony;
- Have the technology to tolerate the life-rating of the area.
All nations start with a life-rating minimum of 35. Most colonial areas only have a life-rating of 15. However, you can lower your minimum allowed life-rating through research:
- Industry tech: Prophylaxis Against Malaria (Medicine) (1836)
- Culture tech: Nationalism & Imperialism (1850)
- Army tech: Machine Guns (1870)
Once all the requirements are met, select the "Colonize" national focus on your target to began the colonization process. Since most uncolonized areas are out of reach until both Machine Guns and Nationalism & Imperialism are researched, large scale colonization will not begin until 1870 at least. However for a colonial power to succeed, it would be important to prepare naval bases and rack up focus points in the years prior.
Conversion to a full state
To convert a colony to a full state it is necessary to have 1% bureaucrats in the colony state in your accepted culture. In general, having this number of bureaucrats is achievable once an acceptable culture makes up approximately 5% of the population of the colony. There is a greyed out button next to the national focus icon that tells you your progress, when that number is reached, you may press the button to convert the colony into a state. A colony may only be converted to a state when you are not at war. Note that due to these requirements, the vast majority of colonies in the game will never be able to convert to states.
Factories can only be created in states, so creating states can help a country's industry.