AI personalities

Version

This article is considered accurate for the current version (2.2) of the game.

This article is for the PC version of Stellaris only.

AI empires act and behave based on their AI Personality type which in turn is dictated by factors like what ethics, traits and government type the empire has. The personality type will direct the empires' behavior in terms of foreign- and domestic policy, fleet budgeting, political behavior and general empire characteristics. The empire's personality can be found in the diplomacy screen, just under the ethics list.

Behavior

AI behavior can be broken down into characteristics and behavior modifiers:

Characteristics

Characteristics determine whether an empire will take certain actions or not:

• Attack neutrals - Attacks neutral entities (Tiyanki, Nomads, Enclaves, Caravaneers and the Infinity Machine)
• Conqueror – Uses the Claim Wargoal during offensive or defensive wars
• Displacer - Uses the Displacement Purge policy against xeno pops and does not accept refugees
• Dominator – Invades pre-FTL civilizations
• Infiltrator – Uses the Covert Infiltration Observation mission when dealing with pre-FTL civilizations
• Isolationist - Always keeps borders closed and does not accept refugees
• Liberator – Uses the Liberation Wargoal during offensive or defensive wars
• Multispecies – Gives all species Full Citizenship rights
• Opportunist – Is likely to attack another empire if that empire is fighting a war
• Propagator - Aggressiveness changes to 10 when it can't expand
• Purger – Purges xeno pops
• Robot exploiter – Uses the Servitude Artificial Intelligence policy
• Robot liberator – Uses the Citizen Rights Artificial Intelligence policy
• Slaver – Enslaves aliens
• Subjugator – Adopts the Domination tradition tree early and uses the Subjugation Wargoal during offensive or defensive wars
• Uplifter – Uplifts pre-sapients and technologically enlightens pre-FTL civilizations

Behavior modifiers

Behavior modifiers indicate the modification of certain common actions happening as compared to a generalized norm (1.0x).

• Aggressiveness – Affects the chance of declaring wars against empires they hold negative Attitude towards.
• Border friction – Affects how much negative Opinion Border Friction generates.
• Bravery – Affects how much Relative Power is considered when declaring Rivalry or War.
• Colony spending – Affects how many resources the empire will spend in setting up new colonies.
• Combat bravery - Affects the chance of retreating from battle. At 1.0 they will attempt to retreat from an engagement after losing 50% of their fleet.
• Military spending – Affects how many resources the empire will spend on its fleets and armies.
• Threat concern – Affects how much negative Opinion Threat generates.
• Trade willingness – At 1.0 willingness the empire will accept a deal that is equally good for both sides. Lower values mean the empire will only accept deals shifted in its favor.

Ships

• Weapon preference - Preferred weapon type the empire will use on its ships.
• Hull ratio - Amount of hull boosters the empire will have on its ships.
• Armor ratio - Amount of armor the empire will have on its ships.
• Shields ratio - Amount of shields the empire will have on its ships.

The above ratios determine what percentage Hull/Armor/Shield attachments the empire's ship designs will have. As an example, an empire with 0.5x Shield ratio and 0.5x Armor ratio will use ship designs where the Utility slots will contain Defense components consisting of 50% Shields and 50% Armor.

AI personalities

When the game is started the personality with the highest weight will be assigned to the AI empire. All existing weight modifiers are additive, not multiplicative.

Note: Any behavior modifier listed above that is not included in a given entry in the below table means its value is equal to the norm (1.0x).

Regular empires

Personality	Characteristics	Behavior modifiers	Prerequisites	Weight & Modifiers	Description
Honorbound Warriors	Conqueror Dominator Multispecies Subjugator –50 Opinion towards pacifists –100 Opinion towards fanatic pacifists In Apocalypse they will not hire mercenaries	1.75x Aggressiveness 1.5x Bravery 2x Combat bravery 0.9x Colony spending 1.2x Military spending 0.75x Threat concern 0.7x Trade willingness 0.2x Hull ratio 0.4x Armor ratio 0.4x Shields ratio Strike Craft weapons preference	Is either: Fanatic Militarist and one of the following: Egalitarian Xenophile Spiritualist Militarist and Fanatic Xenophile	Base: 50	Honorbound Warriors value honor and martial prowess above all other things. They will seek out worthy foes to fight and have little respect for weaklings and pacifists.
Evangelizing Zealots	Conqueror Dominator Opportunist Slaver –100 Opinion towards Materialists	1.25x Aggressiveness 1.2x Border friction 1.1x Colony spending 1.1x Military spending 0.9x Threat concern 0.75x Trade willingness 0.1x Hull ratio 0.5x Armor ratio 0.4x Shields ratio Kinetic weapons preference	Spiritualist Is either: Authoritarian Militarist Xenophobe Is not: Pacifist	Base: 10 +2 if Fanatic Spiritualist +2 if Fanatic Authoritarian +1 if Charismatic trait +1 if Conformists trait –1 if Repugnant trait	Evangelizing Zealots seek to spread their faith across the galaxy, and are not above using military might to force others to accept their beliefs.
Erudite Explorers	Conqueror Infiltrator Multispecies Opportunist Robot Liberator Subjugator Uplifter	0.75x Aggressiveness 0.75x Bravery 0.5x Border friction 0.9x Military spending 1.2x Threat concern 0.9x Trade willingness 0.3x Armor ratio 0.7x Shields ratio Energy weapons preference	Materialist Is not: Militarist Pacifist Xenophobe	Base: 10 +2 if either: Science Directorate Illuminated Autocracy +2 if Fanatic Materialist +2 if Intelligent trait +1 if Industrious trait +1 if Natural Engineers trait +1 if Natural Physicists trait –2 if Imperial authority	Erudite Explorers value exploration and discovery process above all other things. They will gladly trade for the knowledge they seek, but are not above taking it by force if it proves necessary.
Spiritual Seekers	Infiltrator Liberator Multispecies Robot Exploiter Uplifter	0.25x Aggressiveness 0.75x Bravery 0.25x Border friction 0.8x Military spending 1.1x Threat concern 0.9x Trade willingness 0.2x Hull ratio 0.4x Armor ratio 0.4x Shields ratio Energy weapons preference	Spiritualist Is either: Egalitarian Pacifist Xenophile Is not: Militarist Xenophobe	Base: 10 +2 if Fanatic Pacifist +2 if Fanatic Xenophile +2 if Extremely Adaptive trait +1 if Adaptive trait +1 if Democratic authority –1 if Nonadaptive trait	Spiritual Seekers believe that all life is connected through some higher power that can be understood through its creations. They will seek peaceful cooperation with other empires in the hopes of studying their connection to the divine.
Ruthless Capitalists	Conqueror Infiltrator Multispecies Opportunist Robot Exploiter Slaver Subjugator	0.5x Bravery 0.5x Border friction 1.1x Colony spending 0.1x Hull ratio 0.4x Armor ratio 0.5x Shields ratio Kinetic weapons preference	Corporate authority or Corporate Dominion civic Is either: not Xenophile Militarist Is not Pacifist	Base: 100	Ruthless Capitalists are willing to go to any length to acquire more wealth and resources for themselves and for their empire. They tend to avoid evenly matched fights, preferring to pounce on the weak and helpless.
Peaceful Traders	Infiltrator Liberator Multispecies Opportunist Robot Liberator Uplifter	0.5x Aggressiveness 0.5x Bravery 0.25x Border friction 1.1x Colony spending 0.9x Military spending 1.3x Threat concern 0.1x Hull ratio 0.4x Armor ratio 0.5x Shields ratio Strike Craft weapons preference	Corporate authority or Corporate Dominion civic Is either: Pacifist Xenophile Is not: Militarist	Base: 100	Peaceful traders are chiefly concerned with the flow of commerce, and prefer trading to fighting.
Hegemonic Imperialists	Conqueror Dominator Opportunist Robot Exploiter Slaver Subjugator	1.5x Aggressiveness 1.5x Border friction 1.1x Military spending 0.8x Trade willingness 0.5x Armor ratio 0.5x Shields ratio Energy weapons preference	Is either: Authoritarian Militarist Xenophobe Is not: Pacifist	Base: 5 +1000 if Barbaric Despoilers civic	Hegemonic Imperialists consider themselves the rightful rulers of the galaxy, and will attempt to expand their empire by any means possible.
Slaving Despots	Conqueror Dominator Opportunist Slaver Subjugator	1.5x Aggressiveness 0.5x Bravery 0.9x Colony spending 1.1x Military spending 0.8x Trade willingness 0.3x Hull ratio 0.3x Armor ratio 0.4x Shields ratio Guided weapons preference	Slaver Guilds civic Is not: Pacifist Xenophile	Base: 200	Slaving Despots are slave societies that rely on military expansion to secure a steady supply of slaves for their mines and farms. They prefer to attack the weak and defenseless.
Decadent Hierarchy	Opportunist Robot Exploiter Slaver	0.5x Aggressiveness 0.5x Bravery 0.75x Border friction 0.9x Colony spending 1.1x Military spending 1.1x Threat concern 0.9x Trade willingness 0.2x Hull ratio 0.3x Armor ratio 0.5x Shields ratio Kinetic weapons preference	Slaver Guilds civic Is either: Pacifist Xenophile	Base: 200	Decadent Hierarchies are isolationist slave societies that have few concerns aside from maintaining their rigid way of life.
Democratic Crusaders	Conqueror Infiltrator Liberator Multispecies Robot Liberator +25 Opinion towards Democratic authority –50 Opinion towards oligarchic governments –100 Opinion towards autocratic governments –100 Opinion towards Rogue Servitor	1.25x Bravery 0.75x Border friction 1.2x Military spending 1.1x Threat concern 0.9x Trade willingness 0.1x Hull ratio 0.5x Armor ratio 0.4x Shields ratio Kinetic weapons preference	Egalitarian Militarist Democratic authority Is not: Xenophobe	Base: 100	Democratic Crusaders believe that it is their moral imperative to spread their democratic way of life. They tend to get along well with other democracies, but are more than willing to use military force to "liberate" the populations of less democratic empires.
Harmonious Collective	Multispecies Robot Exploiter Uplifter	0.5x Aggressiveness 0.75x Bravery 0.5x Border friction 1.1x Colony spending 0.8x Military spending 0.75x Threat concern 0.9x Trade willingness 0.6x Armor ratio 0.4x Shields ratio Guided weapons preference	Authoritarian Is either: Pacifist Xenophile Is not: Militarist Xenophobe	Base: 10 +1 if Conformists trait +1 if Imperial authority	Harmonious Collectives are authoritarian societies where the citizens are devoted to the state without the need for coercion. They are usually friendly towards others, so long as they do not meddle in their internal affairs.
Federation Builders	Liberator Multispecies Opportunist Robot Liberator Uplifter	0.75x Aggressiveness 1.25x Bravery 0.25x Border friction 1.2x Threat concern 0.95x Trade willingness 0.1x Hull ratio 0.3x Armor ratio 0.6x Shields ratio Energy weapons preference	Is either: Fanatic Egalitarian Fanatic Xenophile Pacifist and Egalitarian Pacifist and Xenophile Pacifist and Materialist Xenophile and Egalitarian Is not: Authoritarian Militarist Xenophobe	Base: 5	Federation Builders consider all sentient life to have value and will seek to form a strong federation to protect themselves and others from expansionistic empires.
Xenophobic Isolationists	Displacer Isolationist Opportunist Robot Exploiter In Apocalypse they will not hire mercenaries	0.5x Aggressiveness 0.75x Bravery 2x Border friction 1.2x Military spending 0.75x Threat concern 0.5x Trade willingness 0.1x Hull ratio 0.3x Armor ratio 0.6x Shields ratio Guided weapons preference	Pacifist Xenophobe	Base: 12 +1000 if Inwards Perfection civic +1 if Repugnant trait +1 if Sedentary trait –1 if Charismatic trait –1 if Nomadic trait	Xenophobic Isolationists want little to do with the rest of the galaxy, preferring to stay within their borders and have as few dealings with aliens as possible.
Fanatical Purifiers	Attack neutrals Conqueror Dominator Opportunist Purger Robot exploiter Slaver –1000 Opinion towards xenos	2x Aggressiveness Border friction 1.25x Combat bravery 1.2x Colony spending 1.2x Military spending 0.5x Trade willingness 0.1x Hull ratio 0.4x Armor ratio 0.5x Shields ratio Kinetic weapons preference	Fanatic Xenophobe and Militarist Fanatic Purifiers civic if Utopia is installed	Base: 1000	Fanatical Purifiers view all alien life as a cosmic mistake and seek to purify the galaxy of its taint. They will never engage in diplomacy with other species.
Migratory Flock	Infiltrator Multispecies Robot Liberator	0.25x Aggressiveness 0.5x Bravery Border friction 1.2x Colony spending 0.8x Military spending 1.1x Threat concern 1.1x Trade willingness 0.2x Hull ratio 0.4x Armor ratio 0.4x Shields ratio Strike Craft weapons preference	Pacifist Xenophile Is either: Nomadic Rapid Breeders Fertile	Base: 50	Migratory Flocks seek to spread their species across the galaxy through peaceful means, and will happily migrate to the worlds of other Empires if permitted to do so.
Fanatical Befrienders	Conqueror Opportunist Infiltrator Multispecies Subjugator Uplifter +100 Opinion towards everyone	2x Aggressiveness 1.5x Bravery Border friction 1.2x Military spending 0.5x Threat concern 0.1x Hull ratio 0.4x Armor ratio 0.5x Shields ratio Energy weapons preference	Militarist Fanatic Xenophile Repugnant trait Solitary trait Venerable trait	Base: 100	Fanatical Befrienders are highly friendly but deeply lonely individuals. They will attempt to make friends by any means necessary.
Metalheads	Attack neutrals Conqueror Dominator Infiltrator Opportunist Purger Robot Liberator No unique dialogue –1000 Opinion towards everyone	10x Aggressiveness 10x Bravery 1.25x Combat bravery 1.2x Colony spending 1.2x Military spending 0.5x Armor ratio 0.5x Shields ratio Energy weapons preference	Militarist Materialist Xenophobe Industrious trait Strong trait	Base: 1000	Metal.

Hive Minds

Personality	Characteristics	Behavior modifiers	Prerequisites	Description
Hive Mind	Conqueror Displacer Dominator Opportunist Slaver Propagator	2x Aggressiveness 1.5x Border friction 1.2x Colony spending 0.75x Threat concern 0.7x Trade willingness 0.4x Hull ratio 0.2x Armor ratio 0.4x Shields ratio Kinetic weapons preference	Hive Mind Is not: Devouring Swarm	Hive Minds concern themselves with the propagation of their species above all else. So long as they have room to expand, there is little to fear from them, but if boxed in they will think nothing of seizing worlds and slaughtering their native population.
Devouring Swarm	Attack neutrals Conqueror Dominator Opportunist Purger –1000 Opinion towards everyone	3x Aggressiveness 1.1x Bravery 1.25x Combat bravery 1.2x Colony spending 1.2x Military spending 0.4x Hull ratio 0.2x Armor ratio 0.4x Shields ratio Kinetic weapons preference	Hive Mind Devouring Swarm	Devouring Swarms have a single-minded devotion to self-propagation and view all other forms of life as prey to be consumed. They are not amenable to diplomacy in any form.

Machine Intelligences

Personality	Characteristics	Behavior modifiers	Prerequisites	Description
Machine Intelligence	Conqueror Displacer Opportunist Robot Liberator Slaver	1.25x Border friction 1.2x Colony spending 0.75x Threat concern 0.8x Trade willingness 0.2x Hull ratio 0.4x Armor ratio 0.4x Shields ratio Energy weapons preference	Machine Intelligence Is not: Determined Exterminator Driven Assimilator Rogue Servitor	Machine Intelligences have largely put their troubles with organic lifeforms behind them, and are usually open to diplomatic exchanges with other spacefaring races.
Driven Assimilators	Conqueror Dominator Opportunist Propagator Robot Liberator	2x Aggressiveness 0.8x Bravery 1.25x Border friction 1.2x Colony spending 1.2x Military spending 0.75x Threat concern 0.5x Trade willingness 0.2x Hull ratio 0.5x Armor ratio 0.3x Shields ratio Kinetic weapons preference	Machine Intelligence Driven Assimilator	Assimilators are machine intelligences driven by a search for knowledge and diversification. Because Assimilators expand their comprehension of the universe by forcibly sublimating and absorbing organic civilizations into their neural mainframe, they tend to be unpopular with organics.
Determined Exterminators	Attack neutrals Conqueror Dominator Opportunist Purger Robot Liberator –1000 Opinion towards organics –200 Opinion towards Rogue Servitors +100 Opinion towards Machine empires +200 Opinion towards Determined Exterminators	2x Aggressiveness 1.5x Combat bravery Border friction 1.2x Colony spending 1.2x Military spending 0.1x Hull ratio 0.4x Armor ratio 0.5x Shields ratio Guided weapons preference	Machine Intelligence Determined Exterminator	Exterminators are machine intelligences who view all sapient organic lifeforms as an intolerable threat to the galaxy. Thought they may cooperate with other machines, exterminators are unlikely to interact with organic empires in any capacity beyond attempting their annihilation.
Rogue Servitors	Conqueror Infiltrator Opportunist Robot Liberator Subjugator Uplifter	0.75x Aggressiveness 1.25x Bravery Border friction 1.1x Colony spending 1.1x Military spending 0.75x Threat concern 0.9x Trade willingness 0.4x Armor ratio 0.6x Shields ratio Energy weapons preference	Machine Intelligence Rogue Servitor	Having come to the conclusion that organic leadership is fraught with chaos and self-destructive tendencies, Servitors are machine intelligences focused on ensuring organics live a safe and comfortable existence, even if that means co-opting their civilization.

Fallen empires

Fallen empires have unique personalities compared to regular AI empires. They always have only one fanatic ethic.

Sleeping fallen empires
Personality	Characteristics	Behavior modifiers	Prerequisites	Description
Keepers of Knowledge	Robot Exploiter Can send requests, tasks and gifts Can become Guardians of the Galaxy	2x Bravery Border friction 1.25x Combat bravery Threat concern 0.75x Trade willingness	Fanatic Materialist Stagnant Ascendancy	This Fallen Empire dedicates itself to the hoarding of technologies that it believes should be kept out the hands of young and irresponsible races. Pursuing dangerous lines of research may draw their ire.
Holy Guardians	Isolationist Can send requests, tasks and gifts Cannot become Guardians of the Galaxy	1.5x Aggressiveness 2x Bravery Border friction 1.25x Combat bravery Threat concern 0.5x Trade willingness	Fanatic Spiritualist Stagnant Ascendancy	This Fallen Empire dedicates itself to the preservation and defense of its holy sites. Colonizing systems that they consider sacred is likely to incur their ire.
Enigmatic Observers	Liberator Multispecies Can send requests, tasks and gifts Can become Guardians of the Galaxy –60 Opinion towards genocidal empires	0.5x Aggressiveness 2x Bravery Border friction 1.25x Combat bravery Threat concern	Fanatic Xenophile Stagnant Ascendancy	This Fallen Empire dedicates itself to the study of the younger races. Purging and enslaving other species may draw their ire.
Militant Isolationists	Purger Isolationist Does not send requests, tasks or gifts Cannot become Guardians of the Galaxy	2x Aggressiveness 2x Bravery 1.25x Combat bravery Threat concern Trade	Fanatic Xenophobe Stagnant Ascendancy	The Fallen Empire dedicates itself to the defense of its borders against any intrusions. Colonizing systems that border them is likely to draw their ire.
Awakened fallen empires
Personality	Characteristics	Behavior modifiers	Prerequisites	Description
Watchful Regulators	Conqueror Opportunist Robot Exploiter Subjugator Seeks to make every empire a Satellite Awakened from Keepers of Knowledge	2x Bravery Border friction 1.25x Combat bravery Threat 0.75x Trade willingness	Fanatic Materialist Awakened Ascendancy	This Awakened Empire seeks to control the technological level of all other civilizations in the galaxy. They are likely to attack any empire that will not surrender its technological independence.
Doctrinal Enforcers	Conqueror Infiltrator Seeks to make every empire a Dominion Awakened from Holy Guardians	1.5x Aggressiveness 2x Bravery Border friction 1.25x Combat bravery Threat 0.5x Trade willingness –100 Opinion towards materialists	Fanatic Spiritualist Awakened Ascendancy	This Awakened Empire seeks to impose its religious doctrines on the galaxy. They are likely to attack any empire that will not willingly convert
Benevolent Interventionists	Opportunist Subjugator Uplifter Seeks to make every empire a Signatory Awakened from Enigmatic Observers	0.5x Aggressiveness 2x Bravery Border friction 1.25x Combat bravery	Fanatic Xenophile Awakened Ascendancy	This Awakened Empire seeks to protect the lesser races from each other. They are likely to attack any empire that does not accept their enforced peace.
Jingoistic Reclaimers	Conqueror Dominator Purger Robot Exploiter Isolationist Seeks to make every empire a Thrall Awakened from Militant Isolationists	2x Aggressiveness 2x Bravery 1.25x Combat bravery Threat Trade	Fanatic Xenophobe Awakened Ascendancy	The Awakened Empire seeks to restore its lost dominion over the galaxy. They are likely to attack any empire that does not acknowledge their overlordship.

Machine Fallen Empire

Personality	Characteristics	Behavior modifiers	Prerequisites	Description
Ancient Caretakers	Purger Robot Liberator Can send requests, tasks and gifts Can become Guardians of the Galaxy Enigmatic	2x Bravery Border friction 1.25x Combat bravery Threat concern 0.75x Trade willingness	Machine Intelligence Custodian Matrix	This Fallen Empire is an ancient artificial intelligence that appears to be operating on some sort of caretaker protocol. It behaves erratically but seems to post no direct threat to us.
Galactic Custodians	Purger Robot Liberator Custodial Awakened from Ancient Caretakers during Contingency crisis (66% chance)	2x Bravery Border friction 1.25x Combat bravery Threat concern 0.75x Trade willingness	Machine Intelligence Final Defense Directives	This Awakened Empire is an ancient artificial intelligence acting as a galactic custodian. It will focus all its efforts on defending sapient life against the ongoing crisis.
Rampaging Machines	Purger Robot Liberator Berserk Awakened from Ancient Caretakers during Contingency crisis (33% chance)	10x Aggressiveness 10x Bravery	Machine Intelligence Corrupted Defense Directives	This Awakened Empire is an ancient artificial intelligence that has gone berserk. It is likely to attack anything and anyone around it.

Fallback personality

If the process of assigning an AI personality to an empire fails (usually due to a glitch) and the AI empire in question is left without an assigned personality when the game begins, the game will assign it the Despicable Neutrals personality as a fallback. Otherwise, this personality type should not appear in a normal playthrough.

Personality	Characteristics	Behavior modifiers	Prerequisites	Weight & Modifiers	Description
Despicable Neutrals	None	All at norm (1.0x)	Fallback AI personality	Fallback AI personality	What makes a species turn neutral ... Lust for gold? Power? Or were they just born with hearts full of neutrality?

References

Game concepts