This article is for the PC version of Stellaris only.
An Empire is a group of planets and star systems that are ruled by the same government and controlled by a single player (or AI). Empires may have a variety of governments such as a democracy, oligarchism, despotism or imperial rule.
Ethics are the most defining features of a space empire; they affect the behavior of AI empires, likely technologies, available policies and edicts, valid government types, the opinions of other empires, and - perhaps most importantly - provide the fuel for internal strife in large and diverse empires.
It should be noted that the name of the player empire and its government structure can always be changed in the government window.
Each empire starts with a homeworld that is generated according to a different set of rules than randomly spawned habitable planets. Below is a summary of the different homeworlds and their features. Note that the table shows the number of districts available right at start. Clearing blockers will add to those numbers. Each species has double weight for pop growth on its homeworld.
|Organic||16-20||6||6||7||1 pop blocker (depends on authority)
Two random +2 districts (depends on authority)
|Planetary Features are determined by climate but the total number of districts available is always the same.|
|Machine||16-20||8||6||3||1 pop blocker (depends on civics)
Abandoned Strip Mine
|Machine Intelligence||Does not replace Earth's Planetary Features or blockers.|
|Gaia||25||8||7||8|| Sprawling Slums
Industrial Wasteland (x2)
|Life-Seeded civic||Increases Earth's size but does not replace its Planetary Features, resulting in a smaller number of specialized District slots.|
Adds +1 Bubbling Swamp, Crystalline Caverns and Dust Caverns Planetary Features even if the homeworld is Earth.
|Tomb||16-20||6||6||6|| Settled Ruins
|Post-Apocalyptic civic||Does not replace Earth's Planetary Features or blockers.|
|Tomb||16-20||7||6||3|| Former Organic City
|Determined Exterminator civic||Clearing the Blockers unlocks unique Planetary Features.|
|Earth||16||6||7||5|| Sprawling Slums
Great Pacific Garbage Patch
|Sol starting system||Earth has its own unique set of Planetary Features and blockers.|
Changing the climate of Earth during empire creation will have no effect of the Planetary Features.
The United Nations of Earth and Earth Custodianship preset empires start on Earth by default.
|Unity||18||6||6||7||1 pop blocker (depends on authority)
Two random +2 districts (depends on authority)
|Deneb starting system||It is identical to regular starting planets in every way except that its size is fixed at 18.|
The Commonwealth of Man preset empire starts on Deneb by default.
The capital is the ruling seat of an empire and is oftentimes its most important world. An empire's capital can be moved once every 10 years for a cost of 250 influence. The capital is its own world Designation and gets +5 Stability and +10 Amenities and either +100% Governing Ethics Attraction by default or -20 Deviancy if Gestalt Consciousness. An empire's capital planet and system are marked by star corners on the system and galaxy maps.
Empire Sprawl is a measure of an empire's expansion, both tall and wide, and increases the cost of Technologies, Traditions, Leaders and Edicts. Empire Sprawl is increased by 2 for each system, planet and owned Branch Office and by 1 for each district.
Administrative Capacity represents the bureaucratic assets available to administrate the empire. If the empire exceeds the capacity then every point of Empire Sprawl exceeding the Administrative Capacity will impart the following penalties:
- +0.3% Tech cost
- +0.5% Tradition adoption cost
- +1% Campaign (Certain sorts of Edicts) cost
- +1% Leader Upkeep cost
- +1% Leader Cost
An empire's base Administrative Capacity is 30, increased by the following:
- +10 Pacifist ethic
- +20 Fanatic Pacifist ethic
- +20 Efficient Bureaucracy civic
- +20 Colonial Bureaucracy research
- +20 Galactic Bureaucracy research
- +15 Administrative Efficiency repeatable technology
- +20 Courier Network / Limited Autonomy / Extensible Software Tradition
- +30 Imperial Prerogative ascension perk
- +20 Divided Attention civic
- +20 Corporate authority
- +10 Private Prospectors civic
- +20 Oracle permanent modifier
Assuming that each point added to your empire is equally productive the effect of empire sprawl is to make the rate of your technology, campaign, and tradition production tend to a limit - equivalent to 100 points of admin for campaign edicts, 200 for traditions and 333 for technology. This means that normally going over the administrative capacity of an empire leads to diminishing returns, however if your admin capacity is above one of these limits going over the cap even by just a few points can lead to significant reductions in productivity as your production tends down to the limit. Leader costs are significantly more complex as the number of leaders an empire requires increases as the empire becomes larger.
Empire Cohesion, as the name implies, is a measure of the overall cohesiveness of an empire's territory. If the cohesion loss is greater than the total cohesion an empire's Sprawl will be multiplied and thus put greater administrative strain upon it. Cohesion is raised or lowered by the following:
- +1 for each owned system
- +3 for each upgraded Starbase
- -1 for each hyperlane connection outside the empire's borders
- -3 for each unowned system that only connects to your empire
Empire Cohesion is especially important in games set with a high hyperlane density. Full hyperlane density in particular limits the use of outposts due to every system having on average 6 connections.
Sectors are administrative regions within an empire. Every empire will start with a core sector, named after the homeworld and extending up to 4 hyperlanes away from the capital. Any planet colonized more that 4 hyperlanes away can be selected to create a new sector, with the planet as its capital. The new sector will extend up to 4 hyperlanes away from the new sector capital. Wormholes and Gateways are not counted for this calculation. Each sector can have a Governor assigned to it.
All sectors, including the core sector, can be given a Sector Focus. Choosing a Sector Focus will make the sector develop itself automatically as long as it has resources, reducing micromanagement. Resources can be added to a Shared Stockpile for all Sectors to use or given manually to each Sector.
Victory score tallies an empire's total accomplishment. The empire that has the highest score when the Victory Year arrives is declared winner. The Victory Year is configurable and can be disabled altogether. All players may continue the game session normally even after an empire declares victory.
The Victory Window shows a total score for each empire and its ranking, as well as a breakdown by category. The categories are as follows:
Economic Strength: A weighted sum of all monthly income, including income from trade agreements. Monthly spending is not part of this score. The various resources are weighted the same as their default market price:
- +1 per basic resources
- +2 per Consumer Goods
- +4 per Alloys
- +10 per advanced resources
- +20 per strategic resources
Number of Systems:
- +10 per system
Number of Colonies:
- +50 per colony
Number of Pops:
- +2 per pop, regardless of type
- +50% of a subject empire's score is given to the overlord
- +10% of each other federation member's score is added to all federation members
Crisis Ships Killed
- +10 per crisis ship destroyed
- Unknown, something to do with value of researched techs, perhaps also research production?
- Each Relic grants a large amount of score. The score of each Relic is shown on the Relics page.
Empire Modifiers are gained through a variety of actions such as event choices or diplomacy with enclaves. They affect the entire empire and as such bring large benefits or penalties.
Permanent Empire Modifiers are always positive and last the entire game. They can only be gained through events.
Renewable Empire Modifiers are always positive and last as long as an empire can afford their upkeep costs.
|Available only with the Utopia DLC enabled.|
Shroud modifiers are obtained by trying to get a boon via the Shroud. Being successful will grant a random boon for 5 years but being unsuccessful with grant a curse for 5 years. Boons and curses can grant any of the following:
|Boons of the Shroud||Curses of the Shroud|
The following empires can appear during the game as a result of certain events: