Diplomacy

Version

This article has been verified for the current PC version (3.4) of the game.

Diplomacy

Diplomacy

Relations

Galactic community

Federation

Subject empire

Diplomacy between plantoids and arthropoids

Diplomacy in Stellaris draws on the model of previous Paradox games and offers an alternative to warmongering.

Envoys

Envoys are minor leaders and can be assigned to various diplomatic tasks. Once an envoy is assigned to a task it cannot be reassigned again for a year. Envoys can be assigned to the following tasks:

• Improve Relations with another empire, which grants  +0.25 opinion per month to and from the target empire (up to +100) and removes the relation requirement for positive diplomatic actions
• Harm Relations with another empire, which grants  −0.5 opinion per month to and from the target empire (up to −100) and removes the relation requirement for negative diplomatic actions
• Assign to the Federation, which grants  +1 cohesion per month to the federation
• Assign to the Galactic Community, which grants  +10% diplomatic weight
• Assign to the Galactic Imperium to either strengthen or weaken Imperial Authority
• Assign to a first contact and they will discover the aliens for you
• Assign to build a Spy Network in another empire, which will increase  infiltration over time.

Envoy Capacity can be modified by the following:

Source	Available envoys
Inward Perfection civic	−1
Xenophile ethic	+1
Fanatic Xenophile ethic	+2
Diplomatic Corps civic	+2
Galactic Sovereign / Corporate Sovereign civic	+1
Empath civic	+2
Public Relations Specialists civic	+2
The Federation tradition	+1
Diplomatic Grants edict	+1
Bureau of Espionage edict	+1
Enhanced Surveillance edict	+1

Source	Available envoys
Embassy Complex building	+1
Grand Embassy Complex building	+2
Galactic Union president (level 2)	+1
Hegemony president (level 2)	+1
Trade League president (level 2)	+1
Martial Alliance president (level 3)	+1
Research Cooperative president (level 4)	+1
Interstellar Assembly stage II	+1
Interstellar Assembly stage IV	+2
Shared Destiny ascension perk	+2

Diplomatic actions

Many diplomatic actions have a 10-year cooldown once chosen. Some of these are unilateral while others need to be accepted by both sides which becomes a matter of acceptance. Most diplomatic actions require certain Relations or an envoy being sent to improve or harm Relations.

Maintaining any form of lasting treaty generates Trust, which increases  Opinion. The maximum amount of Trust obtainable is limited by the most valuable treaty between both parties. Finishing the Diplomacy tradition tree grants +50 trust cap. Trust decays if there is no new income.

	Action	Effects					Relations	Requirements	Limit
	Improve Relations	Sends an  Envoy to increase  Opinion up to +100	0	0	50	0	Any	Not Harming Relations	N/A
	Harm Relations	Sends an  Envoy to lower  Opinion up to −100	0	0	50	0	Any	Not Improving Relations	N/A
	Build Spy Network	Sends an  Envoy to build a Spy Network	0	0	50	0	Any	No Spy Network	N/A
	Make Claims	Switches to the Claims interface.	0	0	0	0	Any	Can claim any system	N/A
	Declare War	Enters the Wargoals menu to declare a war	−50	0	50	0	Any	No Truce, pact, or federation with target No branch offices on target's planets	N/A
	Close/Open Borders	Controls border access. The initial stance is determined by the Initial Border Status policy.	−20	0	50	0	Any	No Truce or Rivalry Not available between overlords and subjects	N/A
	Invite to Federation	Invites the target empire to join a Federation. Other Federation members must agree.	+50	+1	100	−2	Excellent	Part of a  Federation Both empires at peace	N/A
	Ask to join Federation	Requests to join an already existing Federation. Other Federation members must agree.	+50	+1	100	−2	Excellent	Existing Federation and requestor both at peace	N/A
	Kick from Federation	Starts a vote to kick the member from the Federation	0	0	50	0	Any	Member of the same Federation At peace	N/A
	Ask to leave Federation	Requests to leave the Federation. Refusing grants the Secession Casus Belli and a decaying −45  Opinion.	0	0	50	0	Any	Hegemony Federation At peace Target is the Federation president	N/A
	Association Status	The empire and the Federation will not be able to declare war upon each other.	+10	+0.50	100	0	Positive Excellent	The majority of federation members must agree to granting or removing the status but the associate member can cancel it at any time	N/A
	Propose Subjugation	Enters the Terms menu to propose becoming overlord	+25	+0.25	50	0	Any	Both empires are at peace	N/A
	Ask to be their Subject	Enters the Terms menu to propose becoming subject	+25	+0.25	50	0	Any	Both empires are at peace	1
	Release Subject	Grants independence to the subject and sets a 10-year Truce	0	0	50	0	Any		N/A
	Integrate Subject	Integrates a Vassal or Protectorate into the overlord empire.	0	0	50	Variable	Any	Integration Permitted term of agreement Sufficient  Influence	1
	Insult	Decaying −200  Opinion Modifier	0	0	50	0	Terrible Tense		N/A
	Add to/Kick from Imperial Council	Decides who is member of the Imperial Council.	0	0	50	0	Any	100  influence Galactic Emperor By Appointment Imperial Council resolution Target is a member of the Galactic Imperium	1-5

Unilateral agreements

Unilateral agreements are diplomatic actions that can only be proposed and ended by one of the empires. Rivalries can only end 10 years after they were proposed.

Agreement	Effects	Relations	Truce if ended						Limit	Target independence
Rivalry	Closes borders and grants the Animosity Casus Belli Reduces claim cost by 20%	Terrible Tense		−100	0	50	+0.5		3	Independent
Guarantee Independence	The guaranteeing empire will join the target's defensive wars	Neutral Positive Excellent		+10	+2.5	50	−0.25		3	Independent
Support Independence	The supporting empire will join the war against the overlord if the subject starts a war for independence The supporting empire's power will be added to the relative power of subjects opinion modifier between the subject and the overlord	Any		0	0	50	0		N/A	Subject
Secret Fealty	The target empire gains the Allegiance War casus belli	Any		0	0	50	0		N/A	Subject

Bilateral agreements

Bilateral agreements are mutually-beneficial diplomatic actions that when offered by an empire the other must accept for them to take effect. Agreements can be ended at any time by either empire but will bring a temporary  Opinion malus. Defensive Pacts and Federations can only be made or broken when neither empire is at war with anyone. Federations also require the The Federation tradition.

Agreement	Effects	Min Relations	Truce if ended	Opinion if ended
Embassy	Envoys improve relations 3 time faster Diplomatic pacts give 20 more  Intel	Neutral		0	0	+0.75	100	0	0
Non-Aggression Pact	Neither empire can declare war upon each other	Neutral		−50	0	+0.50	75	20	−0.25
Research Agreement	+25%  Research Speed for technologies discovered by the other empire	Positive		−25	0	+0.10	50	30	−0.25
Commercial Pact	Both empires will gain the economic bonuses of 10% of each other's  Trade Value	Positive		−25	0	+0.25	50	20	−0.25
Migration Treaty	Pops can migrate between the empires and both empire can use each other's Pops in colony ships	Positive		−15	0	+0.25	50	30	−0.25
Defensive Pact	If either empire is attacked the other will join the war as a defender	Excellent		−100	20	+0.75	100	40	−1
Federation	Neither empire can declare war upon each other If either empire is attacked the other will join the war as a defender Additional effects based on Federation type and laws	Excellent		−200	50	+1	100	70	−0.5

Acceptance

The acceptance of diplomatic agreements by computer empires is determined by multiple factors.

Agreement	Friendly Attitude	Receptive / Cordial / Protective Attitude	Neutral / Wary Attitude	Overwhelming Relative Power	Superior Relative Power	Shared Rival	Opinion	Distance	Other factors
Embassy	+100	+40	−25	+20	+10	+30 per Rival	+5 per 10 Opinion	−0.5 per hyperlane
Non-Aggression Pact	+100	+20	0	+100	+50	+50 per Rival	+2 per 10 Opinion	−1 per hyperlane	−30 per existing Non-Aggression Pact
Commercial Pact	+100	+20	0	0	0	0	+4 per 10 Opinion	−1 per hyperlane	+1 per given Trade Value −30 per existing Commercial Pact
Research Agreement	+100	+20	0	0	0	0	+4 per 10 Opinion	−1 per hyperlane	+1 per tech either empire doesn't have −30 per existing Research Agreement
Migration Treaty	+10	0	0	0	0	0	+5 per 10 Opinion	−1 per hyperlane	+10 Loyal Attitude
Defensive Pact	+50	+20	−50	+20	+10	+30 per Rival	+2 per 10 Opinion	−1 per hyperlane	+30 per shared Defensive Pact −50 per existing Defensive Pact
Federation	+30	0	−50	+20	+10	+10 per Rival	+1 per 10 Opinion	−1 per hyperlane	+100 Federation Associate +30 Crisis −50 Different War Philosophy policy
Subject Demand	+20	0	−50	+100	+50	0	0	−5 per hyperlane	−1 per 4 owned Pops

Personality

The most specific factor that determines an empire's acceptance rate is its AI personality.

AI personality	NAP	Defensive Pact	Research	Commercial Pact	Migration	Galactic Union	Trade League	Martial Alliance	Research Cooperative	Hegemony	Trade Willingness
Decadent Hierarchy	+20	−10	0	0	−100	−30	−30	−30	−30	−10	90%
Democratic Crusaders	0	+20	0	0	0	+10	0	+10	0	−50	90%
Erudite Explorers	+5	+5	+50	+10	0	0	0	0	+10	0	90%
Evangelizing Zealots	0	0	−20	−20	0	−20	−20	−10	−20	−20	75%
Federation Builders	+25	+25	+15	+15	+10	+20	+10	+10	+10	+10	95%
Harmonious Collective	+20	0	+10	+10	−10	0	0	0	0	0	90%
Hegemonic Imperialists	−10	+10	−10	−10	−50	−20	−20	−10	−20	0	80%
Honorbound Warriors	−100	+20	0	−20	0	−10	−20	0	−20	−10	70%
Migratory Flock	+20	0	+20	+20	+100	+20	+20	+10	+20	+10	110%
Peaceful Traders	+20	0	+10	+20	+20	+10	+20	−10	+10	+10	100%
Ruthless Capitalists	−10	0	+10	+20	0	−10	+10	−10	−10	−10	100%
Slaving Despots	−20	0	0	0	−100	−10	−10	−10	−10	0	80%
Spiritual Seekers	+20	+10	+10	+10	+20	+10	+10	+10	+10	+10	90%
Xenophobic Isolationists	+20	−20	−20	−20	−100	−50	−50	−50	−50	−50	50%
Fanatical Befrienders	+50	+50	+50	+50	+50	+50	+30	+30	+30	+30	100%
Fanatical Purifiers	0	0	0	0	0						50%
Hive Mind	−10	−10	0			−50	−100	−30	−50	−50	70%
Machine Intelligence	0	0	0			−30	−100	−20	−20	−30	80%
Rogue Servitors	0	0	0			0	0	0	0	+10	90%
Driven Assimilators	0	0	0			−50	−50	−50	−50	−50	50%
Determined Exterminators	0	0	0								100%
Crisis Aspirant	0	0	0	0	0	0	0	0	0	0	50%
Indolent Overlord	0	0	0	0	0	0	0	0	0	0	25%

Trade deals

Trade deals are instant or monthly transfers of resources or other assets between two empires. Deals that transfer monthly resources last between 10 and 30 years; once the AI fills their stockpile, long-term contracts become only viable option. It is possible to break long-term trade contracts if not enough resources are stockpiled, but this causes an  opinion penalty. Diplomatic trades often can yield better deals than the market. The AI will never accept mixed long-term/instant trades. Although  Gestalt Consciousness empires have no use for  consumer goods or  Zro, they are still willing to trade for them.

Trading requires a neutral or positive attitude between the two empires. Empires holding a negative attitude will accept only gifts. Fallen empires only trade if they are patronizing or enigmatic towards the proposing empire and will never trade strategic resources. Resources cannot be traded between overlords and subjects if the terms of agreement include contribution.

Trade willingness shows how much an empire is open to trading with other empires and is dependent on their AI personality. The lower their trade willingness is, the more favorable a trade deal has to be for them to see it as fair. Empires with less than 75% trade willingness will never make offers.

In addition to resources, the following things can be traded diplomatically:

• Favors: Each favor has a trade acceptance of 10, raised or lowered by the AI empire's trade willingness.
• Communications: Valued based on the number of new contacts. Does not include Enclaves. Fallen Empires always refuse.
• Active Sensor Link: Valued based on distance, neighboring empires being more interested. Allows the empire receiving the link to see everything the granting empire can see. Only available as a timed deal. Fallen Empire always refuse.
• Transfer System: Available only towards neighbors during peacetime, it is the most valued trade option and can be used to offer to cede one of your star systems, usually non-preferred planets that are too expensive to terraform or adapt pops to, or as a way to ease opinion penalty of claims or border tension. The AI will always refuse to accept systems that contain colonized Holy Worlds or border the Militant Isolationists.

Subject trade deals

Subject empires have additional trading options with their overlord:

• Borrow Fleet: Gives the subject temporary control a fleet. Valued based on how much of the total fleet power the fleets represent.
• Pledge Loyalty: Only available from a subject towards the overlord as a timed trade deal; if the subject has  150 opinion or better towards the overlord, it gives  +2.5 loyalty monthly, otherwise +1.5 monthly.
• Share Empire Data: Adds  +20 intel from the giver to the recipient; can be given by the overlord if they have 80 or less intel on the subject; can be given by the subject if they have 40 or less intel on the overlord.
• Loyalty: Only available from a subject towards its overlord, each point of loyalty will increase trade acceptance by 1. Loyalty can be used even if the value would become negative, up to −100.
• Transfer Leader: Requires a tier 2 specialized subject, transfers a subject leader to the overlord. Valued based on the leader's abilities.

Specialist subjects have additional, unique trade options which extend their bonuses to the overlord, usually at the cost of their own:

Type	Trade	Timed	Effect		Overlord	Subject	Multiplied by Tier
Bulwark	Bulwark Prefabs		Defense Platform	Build cost  Upkeep	−25%	+25%
	Bulwark Technology		Researched Bulwark technologies given as options to Overlord Subject gets Bulwark Technology Sharing modifier for 1 year: Reduces shared technologies' type(s) production by −10%
Prospectorium	Prospectorium Techniques		Monthly strategic resources		+5%	−5%
	Prospectorium Technology		Researched Prospectorium technologies given as options to Overlord Subject gets Prospectorium Technology Sharing modifier for 1 year: Reduces shared technologies' type(s) production by −10% Subject pays  100 strategic resources by technology shared
Scholarium	Scholarium Processors		Research station output		+10% + +10%	−5% + −5%
	Scholarium Hypotheses		Research alternatives		+1	−1

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Trade acceptance

The trade acceptance number shows how much the other empire favors a deal. A trade acceptance lower than 1 means that the other empire sees the deal as disadvantageous for them and will always refuse it. A trade acceptance of 1 means that AI empire sees the deal as fair and will always accept it. A trade acceptance higher than 1 means that the other empire sees the deal as advantageous for them and will give a temporary bonus to their  opinion, although this has a limit of +100.

Favors

Favors can be traded via diplomatic trade or obtained through events and have two purposes. First, an empire can call upon Favors to add another empire's Diplomatic Weight to theirs (10%per favor) when voting Resolutions in the Galactic Community as long as they don't already vote identically. This does not decrease the other empire's diplomatic weight for the vote. Second, Favors increase the acceptance rate of certain diplomatic agreements or federation laws by +5 for each Favor. An empire can owe another empire up to 10 Favors.

Multiple empires can call upon Favors from the same target empire.

Attitude

Each empire will have a specific attitude towards other empires dictated by their AI personality, diplomatic interactions and the relative power of both empires.

Attitude	Trade & Pacts	Prefer peace	Other Effects	Requirements	Description
Neutral			none		This Empire does not consider us relevant to their interests.
Wary			none	inferior relative power and shared border	This Empire maintains a cautious attitude towards us.
Receptive			more inclined to accept diplomatic pacts	diplomatic AI personalities	This Empire is interested in closer relations with us.
Cordial			more inclined to accept diplomatic pacts	high opinion	This Empire is amenable to peaceful coexistence and trading with us.
Friendly			more inclined to accept diplomatic pacts and join a federation	high opinion and successful past diplomacy	This Empire views us as a friend and may be willing to form an alliance with us.
Protective			more inclined to accept diplomatic pacts and may propose subjugation	high opinion and superior relative power	This Empire believes that we are weak and need their protection.
Suspicious			none	low opinion	This Empire views us with suspicion and mistrust.
Rival			none	rival with low opinion	This Empire views us as their rival.
Hostile			none	very low opinion	This Empire views us as their enemy. They are likely to attack us if they think they can win.
Domineering			only uses the Subjugation Casus Belli	low opinion and Subjugator AI	This Empire believes that we would make a fine vassal.
Threatened			none	high threat rating	This Empire views us as a threatening menace.
Overlord			none	overlord	This Empire is our overlord.
Loyal			none	subject with positive opinion	This subject is loyal to us.
Disloyal			considers the relative power of other subjects as well	subject with negative opinion	This subject resents its subservience to us.
Dismissive			none	Fallen Empire	This Fallen Empire considers us largely beneath their notice.
Patronizing			may bestow gifts	Fallen Empire with high opinion	This Fallen Empire views us as errant children in need of their guidance. They may deign to bestow gifts of technology, resources or ships on us.
Angry			will send a demand which will grant them Casus Belli if refused	Fallen Empire with low opinion	We have angered this Fallen Empire with our actions, and they may declare war to punish us.
Arrogant			no effect	distant Awakened Empire	This Awakened Empire views us with dismissive arrogance.
Imperious			will propose subjugation	neighbor Awakened Empire	This Awakened Empire views us as a future subject. They are likely to demand we surrender our independence.
Belligerent			none	Awakened Empire with low opinion	This Awakened Empire views us as a target of conquest. They are likely to attack us.
Custodial			accepts joining a Federation	Guardian Awakened Empires	This Awakened Empire believes that it needs to protect us from the crisis currently threatening the galaxy. They are likely to attempt to ally us.
Enigmatic			opinion is hidden and has no impact	Ancient Caretakers	This Fallen Empire is an ancient artificial intelligence that behaves in a strange and unpredictable manner. We do not know what to expect from it.
Berserk			attacks any empire nearby	Malfunctioning Custodians	This Awakened Empire is an ancient artificial intelligence that has gone berserk. It is likely to attack anything and anyone around it.

Genocidal Diplomacy

Empires with the  Fanatic Purifiers civic can only engage in diplomacy with empires of the same primary species. Note that this other empire will still have −1000  Opinion towards Fanatic Purifier, unless it is also a Fanatic Purifier (in which case they have +200  Opinion towards each other).

Empires with the  Determined Exterminator civic can only engage in diplomacy with empires with  Machine Intelligence authority or the Synthetic Evolution Ascension Perk.

Empires with the  Devouring Swarm or Terravore civics cannot engage in diplomacy at all, not even with identical empires.

References

Game concepts