AI players

Version

Please help with verifying or updating older sections of this article. At least some were last verified for version 3.9.

This article is for the PC version of Stellaris only.

AI players refers to regular empires that are controlled by the AI. Unlike human players the AI is relatively predictable as it follows scripted guidelines.

Personalities[]

While the below is the general behavior of all AIs, the personalities of some AIs will alter or even overwrite some of the behaviors. For the full list of personalities and how they affect the AI, see AI Personalities.

Expansion[]

AI players will always build Starbases in systems that have various features in the following order: Gateway/Wormhole/Colonizable > Natural resources > Other systems
AI players will always upgrade Starbases in systems that have various features in the following order: Gateway/Wormhole > Megastructure > Colony > Habitable planets > Choke point > Uninhabitable systems
AI players will only build starbases up to two hyperlanes away from their controlled system
AI players will only colonize worlds that have at least 35% Habitability for any of their species
AI players will always try to have 1 colony ship, 4 construction ships and 4 science ships, one of which is always used for assisting research on the capital system.
AI players will always construct their first habitats in the core sector.
AI players will always construct their first Hyper Relay in the capital system and then in the adjacent systems.
At a certain point, AI players may recall their science ships and have them assist research on other planets if there is little point to exploring and surveying the galaxy further.

Claims[]

AI players that are independent will only make Claims on systems up to 4 hyperlane jumps from their borders
AI players that are subjects will only make Claims on systems up to 2 hyperlane jumps from their borders
AI players will always claim systems that have various features in the following order: Bordering them > Colony > Gateway/Wormhole > Natural resources > Other systems

Aggressiveness[]

AI players are 2 times more likely to declare war if they can't expand in systems with habitable planets
AI players are 4 times more likely to declare war if they can't expand in any system
AI players are 10 times more likely to declare war if they can't expand and are Hive Mind or Driven Assimilator

Warfare[]

AI players will only declare one war at a time
AI players will only declare war when they use at least 50% of their naval capacity and have at least 6 assault armies
AI players will only attack systems if their Fleet Power is 20% stronger than that of the opponent’s
AI players will always retreat when they lost 50% of a fleet in a space battle
AI players will never retreat if they own less than 3 systems
AI players will never defend attacked systems if their Fleet Power is lower than that of the opponent’s
AI players will never upgrade ships while at war
AI players will go over their fleet limit when at war or in preparation for war.
AI players will always use Selective orbital bombardment stance if their attitude is not hostile
AI players will always use highest available orbital bombardment stance if their attitude is hostile
AI players will never Jump into an enemy system unless its fleet has at least 33% more Fleet Power
AI players will always attack targets in the following order: Occupied systems > Fleets weakened by use of Jump Drive > Systems with colonies > Upgraded Starbases / Fleets / Systems they claimed > Other targets

Slave Market[]

AI players will not buy slaves if they have less than 1000 Energy
AI players will not sell slaves if they have more than 3000 Energy
AI players will always sell a Pop if they have at least 3 Unemployed Pops on a planet
AI players will always sell a Pop if they have at least 6 Unemployed Pops across the empire

Ships[]

AI players will always use private colony ships if they can build them.
AI players will always build a titan if they have the technology. It will build a second one if it has the resources but will never try to have more than two.
AI players will only build a star-eater if both initial ones were destroyed.

Other[]

AI players will never use Ambition Edicts until they unlocked all Traditions
AI players will never Embrace a Faction unless more than 50% of its population belong to it
AI players will never sell more than 30% of their stockpile for any resource
AI players will not send a diplomatic request of the same type for 27 years if the previous one was rejected
AI players will only consecrate habitable planets that have below 35% Habitability
AI players will only attack Leviathans if they have at least 40k Fleet Power
AI players that are Genocidal will attack enclaves once their Fleet Power is twice stronger
AI players will only use Sacrifice Edicts if at least 60 years passed and they have at least 3 Mortal Initiate jobs taken
AI players will infiltrate empires in the following order: Rival > Crisis Level 2 > Neighbor (not same federation) > Other empires
AI players will never use monthly trades on the market, they will always buy in bulk
AI players will end any Secret Fealty if their Loyalty reaches at least 30
AI players will only strengthen Imperial Authority if their relations with the galactic emperor are Positive or Excellent

Economy[]

AI players will always try to have the following surplus:

Income	Condition
+25 Energy	Always
+50 Minerals	Always
+4 Exotic Gases	Always
+4 Rare Crystals
+4 Volatile Motes
+10 Food	Uses the resource
+70 Engineering Research	> +10 Consumer Goods if not Gestalt Consciousness > +30 Minerals if Hive Mind > +25 Energy if Machine Intelligence
+70 Physics Research
+70 Society Research
+15 Alloys	Machine Intelligence
+10 Consumer Goods	Uses the resource > +25 Energy > +50 Minerals > +10 Food if uses the resource
+20 Food	Uses the resource > +70 Engineering Research > +70 Physics Research > +70 Energy Society Research
+9000 Pops	> +25 Energy > +50 Minerals > +70 Engineering Research > +70 Physics Research > +70 Society Research

Once all objectives aside from pops and advanced resources have been achieved the AI will increase all values by the following:

+10 Energy
+10 Minerals
+10 Unity
+10 Alloys
+25 Engineering Research
+25 Physics Research
+25 Society Research
+1 Consumer Goods if uses the resources

Once all new values have been reached the AI will increase them again, repeating the process.

Army Composition[]

AI players will always try to have 10 armies, with an additional army for every 50 Pops up to a cap of 50 armies. They will always recruit only one type of army, with the following conditions:

Army	Conditions
Assault Army	Telepathy technology Gene Seed Purification technology Neural Implants technology and uses slaves Droids technology and Artificial Intelligence policy is set to Citizen Rights Gene Banks technology and Militarist or Fanatic Militarist
Slave Army	Neural Implants technology and uses slaves Telepathy technology Gene Seed Purification technology Gene Banks technology and Militarist or Fanatic Militarist
Robotic Army	Droids technology and Artificial Intelligence policy is set to Citizen Rights Telepathy technology Gene Seed Purification technology
Clone Army	Gene Banks technology and Militarist or Fanatic Militarist Telepathy technology Gene Seed Purification technology
Psionic Army	Telepathy technology Gene Seed Purification technology
Gene Warrior Army	Gene Seed Purification technology
Hunter-Killer Army	Adaptive Combat Algorithms technology
Battle Frame Army	Adaptive Combat Algorithms technology

Relics[]

AI players will use the following weights when activating a Relic:

Relic	Weight
Crystal of Odryskia	50
Isolated Contingency Core	100
Prethoryn Brood-Queen	100
Scales of the Worm	100
Ether Drake Trophy	100
Cybrex War Forge	100
Javorian Pox Sample	100
Vultaum Reality Perforator	100
Yuht Cryo Core	100
Blade of the Huntress	100
Head of Zarqlan	100
The Last Baol	100
The Key	100
The Surveyor	120
Psionic Archive	200
The Galatron	200
Vacuum Flower	200

Relic	Weight
Extradimensional Warlock	10 x30 if at war x0 if it has neither version of Jump Drive
The Rubricator	75 150 if below 500 Minor Artifacts
Khan’s Throne	100 x2 if Militarist or Fanatic Militarist x3 if at war
The Defragmentor	100 115 if Machine Intelligence
Miniature Galaxy	100 150 if Materialist or Fanatic Materialist
The Omnicodex	100 200 if Xenophile or Fanatic Xenophile
Maw of the Toxic Entity	1 1000 if Knights of the Toxic God

Megastructures[]

AI players will only construct megastructures when at peace and generally only in systems that are surrounded by other owned systems. They will always prioritize upgrading over constructing new megastructures. They will use the following weights when deciding which megastructure to construct:

Megastructure	Weight
Gateway	5
Ring World	10
Dyson Sphere	15
Matter Decompressor	15
Interstellar Assembly	15
Mega Art Installation	15
Strategic Coordination Center	15
Mega Shipyard	15
Quantum Catapult	15
Science Nexus	10 20 if Materialist or Fanatic Materialist
Sentry Array	10 20 if Militarist or Fanatic Militarist