Terraforming

Version

This article has been verified for the current PC version (3.6) of the game.

Celestial body

Classification

Colonization

Terraforming

Planetary features

Planet modifiers

 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.

Terraforming requirements

Terraforming is started via a button in Planet Detail view. The world must be surveyed and within the empire's borders. Only habitable worlds or uninhabitable worlds that have the  Terraforming Candidate modifier can be terraformed; Frozen and Toxic terraforming candidates further require a specific ascension perk to terraform. The expansion planner screen can also be used to find these candidates.  Relic Worlds and  Ecumenopolises can never be terraformed through the regular mechanics.

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.

Original climate	New climate	Cost	Years	Requirements	Additional requirements
Frozen	Frozen	2000	5	Terrestrial Sculpting technology	—
Dry	Dry
Wet	Wet
Frozen	Dry or Wet	5000	10
Dry	Frozen or Wet
Wet	Frozen or Dry
Barren	Dry	5000	10	Climate Restoration technology  Terraforming Candidate modifier	—
	Wet	10000	15
	Frozen	15000	20
Barren (Cold)	Frozen	5000	10
	Wet	10000	15
	Dry	15000	20
Nanite	Any regular climate	1000	1
Frozen	Ocean	12500	25		Hydrocentric ascension perk
Tomb	Any regular climate	10000	20	Climate Restoration technology	—
Hive
Machine
All regular climates	Gaia	7500	10	World Shaper ascension perk	—
Tomb		12500	25
Barren					Terraforming Candidate modifier
Any habitable	Hive	10000	20	Hive Worlds ascension perk	—
Barren					Terraforming Candidate modifier
Any habitable	Machine			Machine Worlds ascension perk	—
Barren					Terraforming Candidate modifier
All regular climates	Tomb	1000 100 100	10	Relentless Industrialists For Science! Industrialism policy	—
Gaia		2500 200 200	15
Barren		12500	25		Climate Restoration technology  Terraforming Candidate modifier
Toxic	Any habitable except Continental	10000	10	Detox ascension perk  Climate Restoration technology  Terraforming Candidate modifier	—
	Continental		15

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

•  Bleak
• Irradiated
•  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:

•  Atmospheric Hallucinogen
•  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

If the planet is terraformed into a  Machine World, the  Paradise Made modifier is also removed. Additionally, if there are any  Pops on the planet without the  Cybernetic,  Mechanical, or  Machine traits, they 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, does not kill  robotic pops
• Deluge Machine Colossus: all pops without the  Aquatic trait are killed, planet is terraformed into an  Ocean World, owned planets can be targeted, if any pops remain, perpetrator gains ownership of the planet if not already owned
• Toxic God Colossus: all pops are killed, all deposits and buildings are removed, planet is terraformed into a  Toxic World, if 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.
• 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.
•  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, and in following instances, the planet is terraformed without any warning.

Colonized planets can also be terraformed by certain decisions. The following decisions will terraform the world to a new class.

	Decision	Cost	New class	Planetary features	Other effects	Requirements
	Arcology Project	10 Years 200 20000	Ecumenopolis	Removed	Districts are converted based on the current designation	Arcology Project ascension perk All district slots filled with City Districts or Industrial Districts All blockers removed  Habitat  Ring World Shattered Ring World
	Restore Ecumenopolis	10 Years 200 20000	Ecumenopolis	Removed	Adds a Former Relic World planetary feature Districts are converted based on the current designation	Relic World  Anti-Gravity Engineering technology All Blockers removed  Gestalt Consciousness unless  Rogue Servitor
	Repair the Shattered Ring	10 Years 10000	Ring World	No features	Districts are converted into Segments at a ratio of 5:1 Mineral Purification Plants and Mineral Purification Hubs buildings are removed	Shattered Ring World  Mega-Engineering technology All Blockers removed
	Nu-Baol Life-Seeding	2 Years	Gaia World	Kept	The planet is populated with 4  Pacifist plantoid pops that have the  Agrarian,  Communal,  Venerable,  Delicious and  Slow Breeders traits. If the empire has  Hive Mind authority they will also have the  Hive-Minded trait. If the  Plantoids DLC is installed, they will also have the  Phototrophic trait.	The Last Baol relic activation  Habitat  Ring World Shattered Ring World  Ecumenopolis  Hive World  Machine World  Relic World

Cost reduction & speed

 Terraforming cost and speed can be affected by the following:

Source	Cost	Speed	DLC
World Shaper ascension perk	−25%	—
Hydrocentric	−25% to Ocean	—
Secrets of the Baol empire modifier	−15%	—
Shallarian Terraforming Knowledge empire modifier	−10%	+20%
Mask of Transformation empire modifier	−10%	+10%
World Shaper ruler trait	—	+25%
Terraforming Gases edict	—	+50%
Exotic Gases Shortages Situation	—	−20% per stage
Ecological Protection resolution 4	+25%	—
Ecological Protection resolution 5	+100%	—

References

Regular terraforming links are found in Stellaris/common/terraform; special terraforming methods can be found by searching the game files for the effect change_pc.

Game concepts