Subject empire

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This article is for the PC version of Stellaris only.

Diplomacy

Relations

Galactic community

Federation

Overlord redirects here. For the game expansion, see Overlord (DLC).

Vassalization request towards a Machine Intelligence empire

A subject is an empire that has a special diplomatic relationship with another empire, called the overlord. In the default galaxy map mode, subjects have the same color as their overlord.

An empire can become a subject willingly via diplomacy; the acceptance depends on a number of factors, particularly relative power. Additionally, having an overall superior or overwhelming relative power enables an empire to use the Subjugation casus belli to forcefully make another empire a subject.

Subjects, except Satrapies, receive a −50% penalty to their diplomatic weight. In addition, operation difficulty is reduced between subjects and their overlord.

If they have fleets available, subjects' fleets tend to follow their overlord's.

Loyalty[edit | edit source]

Subjects have a secondary opinion type towards their overlord called Loyalty that ranges from −100 to 100. Subjects with negative loyalty have the Disloyal attitude, which prevents any diplomatic agreements; subjects with positive loyalty have the Loyal attitude, which increases acceptance of diplomatic agreements. Loyalty can also be used as part of trade deals between the overlord and the subject.

Loyalty is gained or lost monthly based on subject's opinion and terms of agreements; ethics compatibility, relative power, and overlord holdings have a lesser impact as well. A Pledge of Loyalty can also be negotiated via trade, adding +1.5 monthly loyalty for the duration of the trade deal; if the subject's opinion of the overlord is at least 150, the Pledge of Loyalty adds +2.5 monthly loyalty instead.

If an overlord has multiple subjects, each subject gains −1 monthly loyalty for every other subject. This penalty can be removed by the Feudal Society civic, Franchising civic, or the Shared Destiny ascension perk.

Loyalty also grants experience to specialized subjects. In addition, the Suzerains and Sovereignty resolutions – Intergalactic Directives and Bureaucratic Surveillance – increase or reduce monthly loyalty as well.

Terms of agreement[edit | edit source]

All subjects and overlords have an Agreement towards each other, which may include certain obligations for the subject or the overlord. Agreements may only be changed once every 5 years. Reforming the government to add the Feudal Society or Franchising civics removes incompatible terms from all agreements. Many agreement terms are restricted by subject type, primarily Tributary, or by the Suzerains and Sovereignty resolutions.

The influence cost to propose a change in the Agreement Terms is 50 + 5 for each point of immediate change in loyalty; the total change in loyalty is summed across all terms, so that positive and negative changes can "cancel out" their costs.

For example, changing Holdings Limit from 0 to 1 (or vice-versa) changes loyalty by −5 and thus costs an additional 25 influence; similarly, changing from Sensors from Independent Sensors to Unified Sensors (or vice-versa) changes loyalty by +5 and so also costs an additional 25 influence; however, changing both Holdings Limit from 0 to 1 and Sensors from Independent Sensors to Unified Sensors "cancels out" the total loyalty change and thus costs no additional influence.

Terms	Effects	Immediate	Monthly	Overlord requirements	Subject requirements
Subject Integration
Integration Permitted	Overlord can use the Integrate Subject interaction	−50	−4	Ensured Sovereignty resolution A Voice for All resolution	Ensured Sovereignty resolution A Voice for All resolution Tributary Subsidiary Satrapy Bulwark Prospectorium Scholarium
Integration Prohibited	Overlord cannot use the Integrate Subject interaction	+5	+0.5
Diplomatic Freedom
Limited Diplomacy	Subject cannot engage in diplomacy with other empires Subject cannot vote independently	−15	−1	A Voice for All resolution Feudal Society Franchising	A Voice for All resolution Tributary Subsidiary Satrapy
Restricted Voting	Subject can engage in diplomacy with other empires Subject cannot vote independently Subject joins any Federation the overlord joins (if the federation law allows) Subject joins the Galactic Community if the overlord is part of it	0	0		(Unless either Personal Oversight or A Voice for All resolution passed) Tributary Not Genocidal
Independent Diplomacy	Subject can engage in diplomacy with other empires Subject can vote independently	+5	+0.5	Personal Oversight resolution	Personal Oversight resolution
Expansion
Expansion Prohibited	Subject cannot construct outposts	−15	−1	Ensured Sovereignty resolution A Voice for All resolution Feudal Society Franchising	Ensured Sovereignty resolution A Voice for All resolution Tributary Subsidiary Satrapy Bulwark Prospectorium Scholarium
Expansion Regulated	Subject must pay the overlord an additional 50% of the influence cost when constructing outposts	−5	0	A Voice for All resolution	A Voice for All resolution Tributary
Expansion Permitted	Subject can construct outposts	+5	+0.5	(unless A Voice for All resolution passed) Imperial Fiefdom overlord
Overlord Conflicts
None	The subject joins none of the overlord's wars	0	0		Subsidiary Bulwark
Defensive	The subject joins only the overlord's defensive wars	−10 if not Pacifist −20 if Pacifist	−1		Tributary Satrapy
Offensive	The subject joins only the overlord's offensive wars	−20 if not Pacifist −40 if Pacifist	−2		Tributary
All	The subject joins all of the overlord's wars	−30 if not Pacifist −60 if Pacifist	−3		Tributary Satrapy
Subject Conflicts
None	The overlord joins none of the subject's wars	−10	0	Feudal Society	Tributary Subsidiary Protectorate Scholarium
Defensive	The overlord joins only the subject's defensive wars	+5	+0.5		Satrapy
Offensive	The overlord joins only the subject's offensive wars	+10	+1	Imperial Fiefdom overlord	Tributary Protectorate Scholarium
All	The overlord joins all of the subject's wars	+15	+1.5	Imperial Fiefdom overlord	Tributary Satrapy
Holdings Limit
0	The overlord cannot construct any holdings across the subject's worlds	0	0
1	The overlord can construct 1 holding across the subject's worlds	−5	−0.4		Tributary
2	The overlord can construct 2 holdings across the subject's worlds	−15	−1	Overlord DLC	Overlord DLC Tributary
3	The overlord can construct 3 holdings across the subject's worlds	−30	−2	Overlord DLC Personal Oversight resolution	Overlord DLC Personal Oversight resolution Tributary
4	The overlord can construct 4 holdings across the subject's worlds	−50	−4	Overlord DLC Personal Oversight resolution Borderless Authority resolution	Overlord DLC Personal Oversight resolution Borderless Authority resolution Tributary
Sensors
Independent Sensors	Subject does not receive sensor data from the overlord	0	0	Borderless Authority resolution Franchising	Borderless Authority resolution
Unified Sensors	Subject receives sensor data from the overlord	+5	+0.5		(unless Borderless Authority resolution passed): Tributary

Contribution[edit | edit source]

Contribution terms of agreement dictate whether the subject or the overlord will pay something to the other empire. They are adjustable in 15% increments as a proportion of the subject's income. A negative value means that the overlord pays the subject (a subsidy) and a positive value means that the subject pays the overlord (a tax). Any contribution other than 0% blocks regular diplomatic trading of those resources.

Type	Resources	Immediate	Monthly	Minimum and maximum amounts
Type	Resources	Immediate	Monthly	Vassal	Tributary / Subsidiary	Satrapy	Bulwark	Scholarium	Prospectorium	Protectorate
Basic		0 to −45	+3.7 to −3.7	−45% to +45%	+30% to +75%	+30% to +75%	−75% to −30%	−45% to +45%	+30% to +75%	−75% to +45%
Advanced		0 to −45	+3.7 to −3.7	−45% to +45%	−00% to +75%	−00% to +45%	−75% to −00%	−45% to +45%	+15% to +75%	−75% to −00%
Research		0 to −90	+3.7 to −3.7	−45% to +45%	−00% to +75%	−00% to −00%	−45% to +45%	+30% to +75%	−75% to −30%	−75% to −00%
Strategic		0 to −135	+3.7 to −3.7	−45% to +45%	−00% to +75%	−00% to +30%	−45% to +45%	−45% to +45%	−00% to +75%	−75% to −00%

A Bulwark or Prospectorium's required subsidy (basic and research respectively) increases by 15% for each tier the subject reaches: 45% at tier 2, 60% at tier 3. Additionally, a tier 2 or 3 Prospectorium must pay at least a 30% tax of their strategic resources.

Subject types[edit | edit source]

There are five types of regular subjects, three types of specialized subjects and five types of fallen empire subjects.

Negotiable subjects[edit | edit source]

Type	Subject Requirements	Special Terms	Description
Vassal	Corporate overlord Inward Perfection Within 60% technological difference		A vassal is a subject of another empire, often with little to no self-rule. Having signed a pact with a foreign power, they are often at the whims and mercy of their overlord, forced to bend to whatever rules and regulations their liege wishes. For some weakened empires, this is the final stopgap before they are consolidated properly into the fold, as they are signing away their autonomy bit by bit.
Protectorate	More than 50% technological difference Not converting to specialist subject Imperial Fiefdom overlord	Overlord gains +0.25 monthly influence Subject: Gains −80% research cost Cannot form research agreements	A protectorate is a subject that is considerably weaker than their overlord, reduced to the point where their vassalage is considered a boon to them. Protected from the dangers of the greater galaxy, they can stabilize and improve their homeland as their liege looks out for them.
Tributary	Corporate overlord Within 60% technological difference		A tributary is a fairly autonomous subject, still in charge of their own affairs both internally and politically. They pay a considerable amount of tribute for their overlord's protection, and as long as the money is flowing, they are mostly free to do whatever they want.
Subsidiary	Corporate overlord Within 60% technological difference		A subsidiary is a subject with a considerable amount of self-rule, free to attend to their own affairs. They have signed away some of their independence for a deal where both sides are expected to support and aid one another.
Satrapy	Khan's Throne relic overlord	Subject contributes 30% of their naval capacity to the overlord	A Satrapy is a Subject type continuing the traditions of the Great Khan that is obligated to provide their Overlord with both ships and resources.

Specialized subjects[edit | edit source]

Specialized subjects cannot be integrated and have additional effects. They can gain experience to increase in tier and gain additional effects. To reach tier 2, they need 1200 experience, and to reach tier 3, they need 3600 experience. Experience is gained monthly at a value of a tenth of the subject's loyalty. Empires with the Imperial Fiefdom origin will become a specialized subject of their choice shortly after the game starts. Protectorates cannot be made into a specialized subject; any other regular type of subject can be turned into a specialized subject through the agreement screen.

Overlord effects do not stack if there are multiple specialized subjects of the same type. The Relay Network effects require a Hyper Relay connection between the overlord and subject's capital systems and only apply to overlord systems connected to the same Hyper Relay network.

Type	Effects for subject	Tier 1	Tier 2	Tier 3
Bulwark Overlord gains: Starbase upgrade cost: −20% Starbase upgrade speed: +20% Crime from Relay Network: −10% Stability from Relay Network: +5 Can construct Vigil Command holdings	Starbase damage	+50%	+50%	+75%
	Starbase hull points	+50%	+50%	+75%
	Defense Platform damage	+50%	+75%	+100%
	Defense Platform hull points	+50%	+75%	+100%
	Defense Platform build cost	−25%	−50%	−75%
	Armor hardening	+5%	+15%	+25%
	Shield hardening	+5%	+15%	+25%
	Defense Platform cap	+2	+5	+8
	Hostile daily hull regen starbase aura	—	—	−0.3% (−0.5% with Unyielding completed)
	Monthly energy	−20%	−35%	−50%
	Monthly minerals	−20%	−35%	−50%
	Monthly food	−20%	−35%	−50%
	Admiral Starting level	—	+1	+1
	Admiral level cap	—	+2	+2
	Admirals gain Bulwark traits	—
	Admirals can be traded to the Overlord	—
	Technologies Unlocked	FTL Inhibition	—	—
	Technologies added as research options	Starhold Planetary Shields	Star Fortress Modular Engineering	Citadel
	Can build Battlewright construction ships	—	—

Prospectorium Overlord gains: Mining station build cost: −20% Mining station build speed: +20% Planetary build speed from Relay Network: +25% Building cost from Relay Network: −25% Can construct Offworld Foundry holdings	Mining station build cost	−10%	−25%	−50%
	Monthly energy	+10%	+20%	+30%
	Monthly minerals	+10%	+20%	+30%
	Monthly alloys	+10%	+20%	+30%
	Monthly strategic resources	+10%	+20%	+30%
	Monthly research	−30%	−40%	−50%
	20% Yearly chance to discover a resource cache	Only energy or minerals	Also alloys or strategic resources	Also rare resources
	Governor starting level	—	+1	+1
	Governor level cap	—	+2	+2
	Governors gain Prospectorium traits	—
	Governors can be traded to the Overlord	—
	Technologies added as research options	—	Exotic Gas Extraction Mote Stabilization Rare Crystal Mining	Dark Matter Drawing Living Metal Zro Distillation
	Enables the Strip Mining decision	—	—

Scholarium Overlord gains: Monthly research: +10% Researcher output from Relay Network: +10% Can construct Ministry of Science holdings	Monthly research	+20%	+30%	+40%
	Research alternatives	+1	+1	+1
	Naval capacity	−30%	−40%	−50%
	Military ship build cost	+30%	+40%	+50%
	Military ship upkeep	+30%	+40%	+50%
	20% Yearly chance to discover a research cache	+1000 points of single type	+2000 points of single type	1 in 4 chance: random research option instead of With Discovery completed: +3000 points of single type
	Scientist starting level	—	+1	+1
	Scientist level cap	—	+2	+2
	Scientists gain Scholarium traits	—
	Scientists can be traded to the Overlord	—
	Can build Arctrellis science ships	—	—

Fallen empire subjects[edit | edit source]

Fallen empire subjects have preset terms of agreement. They do not allow subject integration or holdings.

Type	Proposing empire	Diplomatic Freedom	Expansion	Overlord Conflicts	Subject Conflicts	Resource Contribution
Dominion	Doctrinal Enforcers awakened empire	Independent Diplomacy	Expansion Permitted	None	None	Basic 30%
Satellite	Watchful Regulators awakened empire	Independent Diplomacy	Expansion Permitted	None	None	Research 30%
Signatory	Benevolent Interventionists awakened empire	Limited Diplomacy	Expansion Permitted	None	Defensive	None
Thrall	Jingoistic Reclaimers awakened empire	Independent Diplomacy	Expansion Prohibited	None	None	Basic 30%
Scion	Scion origin	Independent Diplomacy	Expansion Permitted	All	None	None

Integration[edit | edit source]

Subjects that have Integration Permitted in the terms of agreement can be integrated into the overlord empire after 10 years via a diplomatic action, transferring ownership of the subject's systems, ships, and relics to the overlord; the subject's leaders, stockpiled resources, and armies are not transferred. Only one subject can be integrated at a time. Integration costs 5 influence per month and has a base cost with the following formula: ${\text{Base cost}}=50+{\text{number of pops}}+(10\,\cdot \,{\text{number of planets}})\$

If the player empire is integrated, the game is automatically lost.

Holdings[edit | edit source]

Main article: Holdings

Overlord holdings are special buildings which can be constructed on subjects' worlds. The max number of holdings across all of a subject's worlds depends on the Holdings Limit agreement term as well as the Bureaucratic Surveillance resolutions.