Colonization

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This article is for the PC version of Stellaris only.

Celestial body

Classification

**Colonization**

Planetary features

Planet modifiers

**Colonization** is the process of establishing control over an uninhabited, habitable planet with a Colony Ship.

The first time an empire colonizes another world, it gains  **12x** engineering output (between **250 ~ 100 000**)

## Habitability

**Habitability** is the measure of how comfortably a species can live on a planet. Most species have a climate preference for one of the primary habitable planet types, although more exotic preferences are possible. A planet's habitability for a given species is determined by how closely its climate matches that species' preference. The 9 regular habitable world types are divided into 3 climate categories: dry, frozen, and wet.  Ring Worlds,  Gaia Worlds, and  Ecumenopolises have maximum habitability for all species, while  Tomb Worlds,  Machine Worlds, and  Hive Worlds (except for  Hive-Minded species) normally have  **0%** habitability for biological species.

* Every **1%** reduction of habitability below **100%** increases pops'  upkeep and  amenities usage by **+1%** and reduces their  job output and  species growth by **−0.5%**. It floors at **0%** Habitability, giving **+100%** pop upkeep and amenities usage, and **−50%** job output and pop growth.
* Homeworlds have **+30%** habitability for the species originating from them.
* Robot pops have **200%** habitability for each planet type.
* Low habitability can trigger various events.

There are four ways to improve habitability:

* Terraforming the planet. This needs a certain technology and may have additional requirements depending on the original planet.
* Using robot pops, which are not affected by habitability. Empires that aren't  Machine Intelligences require the  Droids technology to build colony ships using robots.
* Genetically modifying the climate preference of the pops, which requires the  Glandular Acclimation technology. Since this modifies all pops of that subspecies on the selected world either the planet must be colonized first or an existing world where changing habitability won't be an issue (Gaia World, Ring World, Ecumenopolis, Habitat) should be selected.
* Obtaining alien species with a different climate preference. This can be done by conquest, migration treaty, infiltrating a pre-FTL civilization, uplifting a pre-sapient species, certain events and offers or the  Slave Market. Empires can colonize with any species that has migration access to the empire, even if no pops of that species live on the empire's worlds, provided they have the Colonization Allowed species right.

### Visual cues

Systems containing habitable worlds will have one or more planet icons that are either green, yellow, orange, red, or blue – depending on the habitability percentage and/or status of the planet(s) in question.

 File:Colonizability white.png | World has the  Terraforming Candidate modifier

Planets with an anomaly or a primitive civilization cannot be colonized.

### Improving habitability

Aside from changing climate preference, there are also various other methods for improving habitability:

### Terraforming

Terraforming is the act of changing the planet classification of a planet in order to make it more Habitable for the empire's species. Terraforming technologies requires significant  society research to unlock, and each terraforming project requires large investments of  energy and  time.

The first time a planet is terraformed, there's a chance of triggering a terraforming event. Terraformed planets cannot receive colony events.

A planet must be surveyed and within the empire's borders to be terraformed. It is possible to terraform inhabited planets if the empire has the  Ecological Adaptation technology. Doing so inflicts a  **−20%** happiness penalty on the planet for the duration of the process.

Only the following terraformings are possible:

The following  planet modifiers are always removed when terraforming a planet:

* Bleak
* File:Pm irradiated.png Irradiated
* File:Pm hazardous weather.png Hazardous Weather
* Hostile Fauna
* Wild Storms
* Second Home

If the planet is being terraformed into either a  Machine or  Hive World the following modifiers are also removed:

* File:Pm atmospheric hallucinogen.png Atmospheric Hallucinogen
* File:Pm atmospheric aphrodisiac.png Atmospheric Aphrodisiac
* Lush
* Natural Beauty

If the planet being terraformed was a  Toxic World, the following blockers will be created:

* Poisonous Algae
* Rotten Soil
* Tainted Snowcaps
* Unpleasant Atmosphere
* Venomous Insects

Some planet modifiers make planet unable to be terraformed by standard methods:

* Unstable Tectonics
* Molten Mineral Rivers

If the planet is terraformed into a  Machine World any  Pops on the planet without the  Cybernetic,  Mechanical, or  Machine traits are all killed and an  Organic Slurry deposit is added.

When and if terraforming a planet to Hive or Machine World, keep in mind that all planetary features, excluding a few rare ones that give access to rare resources, will always be removed.

#### Alternative terraforming methods

In addition to the regular terraforming mechanics above, certain events, special projects, decisions, or other actions can change a planet's classification. The following is a partial list:

* Armageddon bombardment: if the last pop is killed, the planet becomes a  Tomb World.
* Javorian Pox bombardment: if the last pop is killed, the planet becomes a  Tomb World. This does not kill  robotic pops.
* Deluge Machine Colossus: all pops without the  Aquatic trait are killed and the planet is terraformed into an  Ocean World. Owned planets can be targeted. If any pops remain, the perpetrator gains ownership of the planet if not already owned.
* Toxic God Colossus: all pops are killed, all deposits and buildings are removed, and the planet is terraformed into a  Toxic World. If the planet was previously habitable it will have the  Toxic Terraforming Candidate modifier.
* The Worm can terraform all planets and moons in the empire's capital system, habitable and uninhabitable alike, into  Tomb Worlds; only  Gas Giants,  Relic Worlds, and  Ecumenopolises are spared. Moreover, the climate preference of every pop living on those planets will be changed to  Tomb World climate preference.
* Gaia Seeders:  Idyllic Bloom empires can build special buildings that will terraform the world into a  Gaia world. They can also build a holding on subjects' worlds to terraform those worlds.
* Every activation of  The Last Baol relic allows one use of the  Nu-Baol Life Seeding planetary decision that terraforms any colonized planet into a Gaia World in 720 days and additionally creates 4 Baol plantoid pops.
* Relentless Industrialists can build  Coordinated Fulfillment Center and  Universal Productivity Alignment Facility buildings which terraform planets into  Tomb Worlds over time. The first time triggers the Environmental Deterioration situation; if the situation reaches maximum, the planet turns into a Tomb World. After the situations ends, *Industrialism* policy is unlocked. If the policy is set to  *Full Steam Ahead* or  *For Science!*, next planets with a  Coordinated Fulfillment Center will be turned into  Tomb Worlds in 30 years and planets with a  Universal Productivity Alignment Facility will turn into  Tomb Worlds in 15 years, this time without any warning. Only chosing  *Cleanup* policy stops this effect.
* The science ship used the the Astrocreator Azaryn legendary paragon has the ability to terraform 3 planets into  Gaia Worlds with the File:Pm overgrowth.png Overgrowth modifier at the cost of  **10000** Energy and 10 years.  Barren Worlds, even without Terraforming Candidate modifier, can be terraformed too but the time is increased to 25 years. The science ship merely starts the process and does not have to stay there.

#### Cost reduction & speed

 Terraforming cost and  speed can be affected by the following:

## Colony ships

Colony ships allow an empire to settle habitable planets or megastructures in owned systems. When ordering the construction of a colony ship, the player is given the option of choosing the species or sub-species of the  pop(s) that will be sent to the new colony. Species require the File:Species right colonization rights.png *Colonization Allowed* species rights to be selected for new colony ships. Pops are neither consumed nor transported in this process. Once constructed, the colony ship may be sent to any habitable world within an owned system to start a colony. Colony ships take one year to build and their upkeep cost is maintained throughout the whole colonization process. Colony ships can also be built through the interface of the planet to be colonized, which automatically queues the colonization order as long as the path is not blocked.

The cost of a colony ship depends mainly on the empire's primary species class and governing authority.

* 200 Food
* 200 Consumer Goods
* 500 Food
  Lithoid | * 200 Alloys
* 200 Minerals
* 200 Consumer Goods
* 500 Minerals
* 500 Minerals

The  Frontier Spirit ruler trait reduces the cost of colony ships by **−35%**.

### Alternative colony ships

In addition to regular colony ships, empires with the  Corporate Dominion or  Private Prospectors civics can also construct **Private Colony Ships**, which cost  500 energy instead.

Similarly, empires with the  Calamitous Birth origin can also construct **Lithoid Meteorites**, which cost  500 minerals instead, have no upkeep cost, and take only 150 days to build. Lithoid Meteorites also have a much faster sublight speed than regular colony ships. A planet colonized by a lithoid meteorite gains two Buried Lithoids blockers and the File:Pm asteroid impacts.png Lithoid Crater modifier.

## Colony development

When a Colony Ship lands on a planet, a period of initial development will occur during which a colony is extremely vulnerable: just a few days of orbital bombardment will wipe it out completely and the new colony will not produce any resources nor will pops grow on the world. It is possible to remove  blockers while the colony is developing, however their clearance cannot be cancelled or reordered until the colony is fully established. Once the colony has been successfully established, it will have a tier 1 capital building and a single pop of the species selected for the colony ship. It is then possible to develop the planet by constructing  districts and  buildings.

The  Colonization Fever tradition and the  Yuht Cryo Core relic each increase the number of initial pops on a new colony by **+1**.  Machine Intelligence empires' colonies also start with **+1** initial pop.

The initial development period lasts about 2 years and 10 months. Colony development speed can also be reduced by the following: