Colonization

This page discusses the mechanism of colonization. For the technology, see Society technology#Colonization

Colonization is the process of taking control of states from nations without a central government.

Establishing colonies

Colonization requires the Colonial Affairs institution, which is enabled by either  Colonial Exploitation or  Colonial Resettlement. These are unlocked by the  Colonization technology, a tier 1 society technology, already researched by many recognized powers at the beginning of the game.

Colonies can be established only in regions where the country has an interest and only in states owned by decentralized nations. The state must also be coastal or border the country. A country can establish any number of colonies, though at most one per eligible state. When the colony is established, a single province is ceded to the colonizing country and the colony begins growing province by province.

Any number of countries can colonize the same state, as long as there are eligible provinces to begin colonization.

Colonial claims

States which are claimed can only be colonized by countries with a claim, unless all of the claiming countries are unable to establish a colony. Once a colony has been started in a claimed state, it continues regularly, even if a claiming country can or does start its own colony afterward.

Colonial growth

The total rate of colonial growth is determined by the total incorporated population and colonial growth generation, which is +0.10% per level of Colonial Affairs. This is capped to a minimum of +0.01 and maximum of +0.1. Total colonial growth is equally split between all colonies, and can be locally modified by events and particularly by  Malaria. A single colony cannot grow faster than +0.02 per day. The base and max rate of colonization is doubled by the Colonial Rights modifier, gained by defeating a native uprising.

Malaria

 Malaria and  Severe Malaria are state traits appearing mainly in Sub-Saharan Africa and Oceania. They decrease colonial growth by −90% and −95% respectively, as well as increasing mortality by 15% and 25% for cultures that do not consider the state in question their homeland.

States with Severe Malaria cannot be colonized at all until the society technology  Quinine is researched, which also disables the effects of non-severe Malaria. The remaining effects of Severe Malaria are disabled by  Malaria Prevention. The effects of Malaria and Severe Malaria do not apply if any of the country's primary cultures considers the state its homeland.

Colonial states

Once a colony is established, the new state is a  Colony. This is a special type of  unincorporated state, namely that it cannot be incorporated until the entire state region is colonized, and it can be abandoned, returning the entire state to a decentralized nation. If a country starts colonizing a state region which already contains its unincorporated state, the unincorporated state becomes a colony until colonization is completed, then returns to being a regular unincorporated state. It is also possible to begin colonizing a state region which contains a country's  incorporated, in that case, the colony remains an incorporated state and it cannot be abandoned.

Tension and native uprising

While a colony is growing, it generates tension with neighboring decentralized nations, between 2.5 and 20 for each province colonized. Tension decays by 5 per year, but if a nation is growing a colony, tension generally continues to increase.

If tension reaches 75 or more, the decentralized nation can begin a Native Uprising – a special diplomatic play – against the colonizing country to retake its homeland and expel the invaders. As a diplomatic play, other nations can support either side as normal. If the decentralized nation wins the play or war, they annex the colonizers colony states in each state region they own part of, while if the colonizer wins, they gain the colonial rights modifier, doubling colonization speed against said decentralized nation for the duration of the truce – 5 years.