A planet's population is the center of productivity and political action. Planets are made up of Population Units (POPs), each of which exists on a specific tile on a specific planet. Tiles that have buildings must also be occupied by a POP in order for the building's effects to be active.
- 1 Growth
- 2 Happiness
- 3 Unemployment
- 4 Ethics divergence
- 5 Consumer goods
- 6 Slavery
- 7 Robots
- 8 Movement
- 9 Purges
- 10 Refugees
- 11 References
Monthly Growth Points
Calculating the Growth Points from food appears to be a multiple Step Process:
- The growth bonus from food surplus is calculated. By default, the value is 1, but having excess food while storage is full will add a percentage to that.
- This value is known as "Planetary Growth Points" (for lack of a better name). Every Planet is given the same amount of "Planetary Growth Points" based on the Empires food surpluss.
- On a planetary level - if multiple species are present - growth points are then split among all growing pops, based on how many pops of their Species are present.
- Percentile Modifiers to Growth are added after this split by species.
- As far as can be seen, all internal math uses a 32 bit signed Integer, where the last 3 digit are displayed as decimal places. Also the application of the Split can varry based on exact version number.
Growth bonus from food surplus:
Only when the storage is full does surplus food produce extra Planetary Growth Points. The Bonus is capped at +100%, but reaching that is near impossible short of the early game.
The Formula is to the best knowledge:
capped at 1 for a 100% bonus.
The base cost to grow a pop is 25, with a penalty based on how many pops are already present. This Formula seems to count every fully grown, food needing Pop on the planet regardless of Species.
Additionally low habitability increases the cost to grow a pop by 
The Formula is: Example values up to 10 existing pops and assuming no habitability effect.
|Current Size||Point Penalty|
Results of the System
- The Growth bonus is 50% if Food Surpluss equals Population and can go up to 100% with twice that amount. Especially early on, a small amount of food surplus can result in a massive increase in growth speed.
- Multiple species planets grow slower, as they do increase each other's growth cost while also splitting the Planetary Growth Points between them.
- Despite this, Species Level growth increases still have an effect, making a quick growing species potentially a lot more present in the long run.
- Planets with low habitability grow significantly slower. This can go into doubling the growth speed easily.
Each pop in an empire has a base happiness rating. The default base happiness for all pops is 50%. If the Pop supports a faction, the happiness of the Faction is used as base happiness instead of the flat 50%. This base happiness then has all sorts of modifiers applied to determine the final happiness rating of a pop. An unhappy pop is less productive than a content one, and produces more unrest. In turn a happy pop produces more resources and has some passive unrest suppression. The max happiness of a pop is determined by its habitability on a certain planet, even if the base happiness is higher than the habitability. On a planet where a species has 40% habitability, the species can only have a maximum of 40% happiness.
The base happiness of a faction, and therefore any pop belonging to it, is determined by how an empire treats a certain faction. Factions have issues related to their values and goals, and how well the empire responds to those issues will determine the overall happiness level of the faction. More details on the specifics of this system can be found on the factions page. In general, adhering to a factions demands will increase happiness, while ignoring or doing the exact opposite of their wishes will decrease their happiness rating. Factions with ethics clashing with the government ethics will also have decreased happiness.
A pop's base happiness is then modified by additional factors, such as civics and rights. Recently conquered populations will tend to be unhappy. Slaves or Purgees will also gain additional unhappiness (on top of having only 50% base happiness), depending on what type of slavery they are being subjected to. When an empire is starving, all biological pops gain unhappiness.
Events may also have an impact on planetary or empire happiness for a limited time.
|Name||Happiness||Food|| Energy Minerals|
|Happy||61 or greater||Up to +20%||Up to +20%|
|Content||40 to 60|
|Unhappy||39 or lower||Up to -20%|
Happiness Bonus and Penalties have no effect when the pop is enslaved.
|Idealistic foundation||+5%||Empire has idealistic foundation civic as government civic|
|Improved Energy Initiative||+5%||Empire has enacted the "Improved Energy Initiative" edict (available through event)|
|Champion of the People||+5%||Ruler has Champion of the People trait|
|Synthetic||+10%||Ruler has Synthetic trait|
|Starvation||-10%||Empire is starving|
|Riggan spice||+5%||Empire has access to the riggan spice strategic resource from a trader enclave|
|Grand Design||+10%||Possible outcome from researching Void Clouds as a Fanatic Spiritualist or Spiritualist (10 years)|
|The Tree||+5%||Possible outcome from special Project "The Tree", the other choice is leader lifespan +20 years|
|Salty||+5%||Temporary bonus from researching an anomaly|
|Purple Rains||+5%||Temporary bonus from researching an anomaly|
|Extradimensionals/Prethoryn defeated||+20%||Gained for beating the Unbidden or Prethoryn crisis|
|Influence deficit||-20%||Empire influence is at 0 and has a negative monthly gain|
|Communal||+5%||Has the Communal trait|
|Solitary||-5%||Has the Solitary trait|
|Fertile||+5%||Has the Fertile trait|
|Psionic||+5%||Has the Psionic trait|
|Recently Conquered||-40%||POP was recently conquered by its current empire (lasts 10 years)|
|Uplifted||+20%||If the pop is an Uplifted Pre-FTL species and is living on a planet ruled by their patron species|
|Enslaved||-10/20/30% depending on the type of slavery||If the pop is Enslaved|
|Citizenship||-5% with residence rights, -10% with caste system (residence) rights||What citizenship rights are given to a certain species|
|Living standards||+40/20/10/0/-10/-20% depending on rights level||What living standards are given to a certain species|
|Population controls||-20% when population controls are enabled||Whether a species is allowed to grow its population or not|
|Xeno Zoo||+10%||The planet has a Xeno Zoo building worked by a pop|
|Paradise Dome||+5%||The planet has a Paradise Dome building worked by a pop (available only to empire with the utopian dream harmony)|
|Plague Memorial||+10%||The planet has a Plague Memorial building worked by a pop (available through event)|
|Loop Institute||+5%||The planet has a Loop Institute worked by a pop (available through Worm in Waiting event chain)|
|Spiral-Feed Power Hub||−5%||The planet has a Spiral-Feed Power Hub worked by a pop (available through Worm in Waiting even chain)|
|Ministry of Culture||+10%|
The planet has a Ministry of Culture worked by a pop (available through event)
The planet has an Art Monument worked by a pop (available through event)
|Stellar Devourer Trophy||+5%|
The planet has a Stellar Devourer Trophy worked by a pop (available through event)
The planet has a Dragonslayer Monument worked by a pop (available through event)
|Ether Drake Shrine||+10%|
The planet has an Ether Drake Shrine worked by a pop (available through event)
A pop that is on a tile that produces no resources is considered "unemployed" and should be moved to a tile where it can be useful. Unemployed POP have a distinct icon on the bottom left corner of the tile. This may be a signal to remove blocked tiles or construct new buildings. Unemployed pops are more likely to migrate if permitted. When there are unemployed pops in the empire, an alert will be displayed.
A materialist pop may decide to follow a more spiritual path and a pacifist culture might decide that peace is the path of the weak. This is called ethics divergence. Each pop in an empire will only embrace a single, non-fanatic ethic. At the start of the game, the population will be made of the ones that were picked. As population expands and eventually is divided over various planets and sectors, certain segments may decide to adopt values that are different from the core values of the species due to various circumstances in and around the empire.
Each ethic has a certain attraction value attached for all pops, depending on both the empire's situation and their own. For example, enslaved pops tend to become more egalitarian. Conversely, fighting a lot of wars will increase the attraction for militarism across the entire empire. The exact values and options that influence the attraction levels of certain ethics can be found at ethics attraction.
The attraction factors of ethics can be amplified by certain actions such as enacting policies or having traits. Especially the governing ethics attraction can be modified. Having a positive ethics attraction effect will let all actions that increase attraction to the government ethics result in even more attraction, and negative amounts will be decreased. With a modifier of 50%, an action that would increase attraction by 2 would instead increase by 3.
Ethics attraction modifiers
Government Ethics Attraction
|Atmospheric Aphrodisiac||-10%||Planet has Atmospheric Aphrodisiac modifier.|
|Atmospheric Hallucinogen||-10%||Planet has Atmospheric Hallucinogen modifier.|
|Reeducation Campaign||20%||Planet has enacted the "Reeducation Campaign" edict (not available to Fanatic Authoritarian).|
|Social Engineering||30%||Planet has enacted the "Social Engineering" edict (only available to Fanatic Authoritarian).|
|Sector||-10%||Planet is managed by a Sector.|
|Capital World||100%||Planet has Capital World modifier.|
|Distance||-0.1% multiplied by the distance from the capital solar system||A planet's distance from the capital solar system.|
|Orbital Mind Control Laser||50%||Planet has a Spaceport with an Orbital Mind Control Laser module.|
Effects are Planet wide, unless otherwise mentioned.
Non Government Ethics Attraction
Promoting a faction belonging to a certain ethic will increase all attraction factors to that ethic by 100%, while suppressing will instead lower all factors by 50%.
- Main article: Consumer Goods
Consumer Goods represents the portion of your industrial base that is occupied with seeing to the needs of your population, i.e. producing butter instead of guns. Each Pop in your empire will use a certain amount of Consumer Goods each month, with the amount primarily dependent on their living standards. Each unit of consumer goods costs a certain number of minerals dependening on factors such as ethics, traditions, whether your empire is engaged in a defensive war and so on. see main article for numbers
- Main article: Slavery
Perhaps unsurprisingly, it is possible to enslave pops, depending upon ethos, species rights and the species in question. As of 1.5, the Slavery Status is based on the Species Rights System. Pops can no longer be enslaved or emancipated specifically.
Slavery can cause both internal and external strife; if the empire's citizens or neighboring empires are opposed to slavery (for instance because they are egalitarian) then this can cause serious faction and diplomatic issues.
As science progresses, creation of robot workers eventually becomes possible. They are exceptionally productive, easy to keep happy (often not having happiness), and able to live and work on any planet surface - unlike most biological species.
All robotic workers cost 150 energy and 50 minerals to build. When built, they progress with a value of 1 per month until fully grown, one at a time per planet. They do not consume food; instead, they cost 1 energy each month. They have the mechanical and appropriate robot traits. Their 200% bonus to habitability from the mechanical trait allows them to operate on any planet type equally well, even Tomb Worlds.
There are three tiers of robotic workers - Robots, Droids, and Synthetics:
- Robots are the first and basic level of robotic workers. They have an advantage at producing minerals, but are disadvantaged at producing energy and produce very little research.
- Droids are the second tier of robotic workers. They have a slight bonus to all yields compared to robots, excluding food.
- Synthetics are the third and final tier of robotic workers. They are good at producing everything including energy and science apart, while having no malus to food production. Unlike Robots and Droids, Synths are sentient and can be granted (or, if oppressed, may demand) rights; doing so makes them equivalent to normal citizens in almost all respects. The only actions that a synth cannot perform is reproducing and being genetically modified.
|Available only with the Utopia DLC enabled.|
- Uploaded Synths are a special case, only available to Empire that underwent full Synthetic Ascension. Effectively these are identical to Synthethics, however they are not Governed by AI rights Policy and are considered a different buildable Robot Species and often a full Xeno Species.
The artificial intelligence policy dictates if robots can or cannot be built:
- When outlawed, no type of robotic worker can be made. Any existing Robot or Robot pop that are aquried via conquest will be purged automatically.
- When set on servitude, synthetics are enslaved (Full Slavery equivalanet).
- The final option, citizen rights, lets synthetics have the rights of regular species. A certain degree of materialist is required for the citizen rights option to be selected.
If the Droids technology is unlocked, all owned Robots pops are automatically upgraded to Droids and the basic robots cannot be built anymore. The same is true for Synthetics and the Synthetic Ascension.
Robotic workers can be a major boon to the production of an empire. However, as research in Artificial Intelligence moves forward, there is a risk of robots gaining sentience and rebelling. See Crisis for details.
Migration is voluntary movement of POPs to a more attractive planet, for example a minority POP of aliens might try to move to its species homeworld. Once migration is activated for a POP, a modifier icon appears on its portrait in the planet surface view and after a certain amount of time it relocates to the destination. Progressive faction will be unhappy if migration controls are enabled for any of the species in the empire. A migration access trade deal with another empire allows migration to foreign territory, in which case the empire of origin loses control over the moving POPs. Only one pop can be migrating to any given planet and away from any give planet at the same time.
The algorithm is currently unknown, but various values are know:
- Minimum Crowding before Migration: 1
- Crowding Effect: 0.25
- Same Species on Target Planet: 1.25
- Distance Effect: 0.01
- Loss of Citizenship: x0
- Gain of Citizenship: x1.2
- Minimum Happiness Difference for Migration: 10%
- Migration Speed: 0.5
Possible Interpretation: Crowding makes planets capable to offer emigration, makes it more likely that a pop emigrate from the planet and less like to attract immigrating pops. There must be at least 4 pops before migration can take place and it always goes from the most densely populated planets to the least densely populated ones.
Resettlement is forced movement of POPs by the government. In order to resettle a POP an empire needs to activate the 'Allowed' Resettlement policy. After that, the resettlement menu can be opened through any POP. Slaves are always eligible for Resettlement. In this menu the planets and POPs involved in the resettlement can be chosen and the resettlement may be implemented at a cost of 50 influence per POP. Resettlement happens instantly (unlike migration), and is a fast way to meet the 5 pop requirement for building planetary administration. Resettlement is not available to Individualist empires. Resettlement does not require Planetary Administration, may be used with sector planets, and requires the pop to be liveable on the planet.
Migration and Resettlement can be enabeled at the same time, but that does carry the risk of pops migrating of necessary places.
As of 1.5 purging is done on a per species basis by setting the target species as undesirables. You cannot declare your primary species undesirables. Pops that can not live on the Planet (too low Habitability) will be automatically Displaced. The purging of Pre-Sentients is controlled entirely via a single policy. Hivemind pops in non-Hivemind empires and non-Hivemind pops in Hivemind empires are automatically Undesireables too. Robot Pops are instead purged via the AI policy.
Having any pops marked as undesirable is a negative issues for various Factions, particularly Xenophiles. Depending on the purge type, a timer will be started for all pops (see Purge Time below). When the time runs out, the purge is completed: all remaining pops of that species will be removed from the players planets. Unless the Purge type is Neutering, the Pop was Pre-Sentient, a Robot Pop or a Hivemind pop a Diplomatic Penalty will be applied to all other Empires based on the Number of Pops purged:
- if the Empire does not have that species as primary species, is not the Purger AI and either a Default Empire or Awakened Xenophile, opinion_genocidal will be applied. The exact effect varies based on Ethics, going from -5 to -20 per pop.
- if the Empire has the same Primary Species, opinion_genocidal_our_species is applied instead and all the other checks are ignored. This penalty is -25 per pop.
Either penalty Stacks up to -1000 and decays at 1 per year. Both can stack. Given the major effect of Purging on other Empires, completing a purge other then Displacement or Neutering will effectively make every other empire in the game hate you for the rest of the game, and hence should be well thought through in all but the smallest cases.
First the Citizenship must be set to "Undesirable". Then the Purge Type can be selected. Options are:
- Displacement: The species is driven away through the use of forced resettlement and destruction of their homes. Displaced pops will not be killed, but rather will attempt to flee the empire to other, more welcoming empires, and might even try to settle uncolonized planets. This process is slow, but generates less outrage among other empires than the other forms of purging. It is available for Authoritarians and will be automatically applied to pops whose habitability is too low on a given planet.
- Extermination: The species is systemically killed off by any means available. This is the fastest form of purging, but pops subject to it are unable to produce any resources while they are busy dying off. This was the only purge type prior to 1.5
|Available only with the Utopia DLC enabled.|
Additional purging types are available by having the Utopia DLC.
- Forced Labor: The species is placed in camps and forced to do hard labor under brutal conditions with inadequate food and shelter, effectively working them to death. Pops doing Forced Labor will be killed off more slowly than through extermination, but will continue to produce minerals, food and (at a significant penalty) energy.
- Processing: The species is processed into food for the consumption of other Pops. Pops being Processed generate a fixed amount of food and die off at a fairly fast pace, but cannot be put to use producing any other resources.
- Neutering: The species is prevented from reproducing through chemical castration or biological modification, eventually dying off naturally. Neutered Pops continue to function normally and may even be given a high standard of life, but have a large penalty to their happiness. The speed at which they die off varies based on the species' natural lifespan, but is typically very slow.
Unless noted otherwise Living Standards are Forcefully set to Non-Existence, they get -10000% Happiness and they still consume food.
As Purge produces unhappiness, considerable Unrest events might be the result. However, there is one additional event of particular note: refugees.2. This one will remove pops under purge over time ("fled to uncharted space"), effectively removing them from the game. This allows Displacement to work without a valid target empire, and will also clear spots on the planet over time to re-populate with ones primary species. It also does not incur any Diplomatic Penalties. The rules for the event are:
- Not Hivemind, Nerve Stapled or Robot Pop.
- Citizenship Purge or unable to live on the planet
- MTTH is 50 years
- x2 if the purge type is Neutering
- x0.25 if the purge type is Displacement
Pops from other empires may flee to escape purges, slavery and resettlement. Whether or not another empire is willing to accept those fleeing depends on your Refugees policy. You can choose to accept other species will open arms, allowing refugee Pops to freely move into your empire, be more restrictive and accept only those Pops you have deigned to grant citizenship, or simply shut down acceptance of refugees altogether.
Refugees can be used to help grow your empire.