Subject empire

Version

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

Vassalization request towards a Machine Intelligence empire

A subject is an empire that has a special diplomatic relationship with another empire of superior strength, 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 scaling negatively with the number of pops the future subject has. Having superior or overwhelming relative power in all three categories enables the Subjugation  Casus Belli to forcefully make an empire a subject.

Operation difficulty is reduced between subjects and their overlord.

If they have fleets available, subject fleets tend to follow the overlord's.

Loyalty

Subjects have a secondary opinion type towards their overlord called  Loyalty that scales from -100 to 100. It determines the subject's attitude towards the overlord and can be spent to increase the acceptance of trade deals. Loyalty is gained or lost monthly based on subject's  opinion and terms of agreements, although ethic 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 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 loyalty instead.

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

Subject empires can only have two attitudes towards their overlord: Loyal if loyalty is positive and Disloyal if loyalty is negative. Loyal attitude grants a bonus acceptance to most diplomatic agreements, while Disloyal attitude prevents the acceptance on any diplomatic agreement.

 Loyalty will also grant experience to specialized subjects. In addition, certain resolutions can raise or lower  loyalty as well.

Terms of agreement

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 will remove incompatible terms from all agreements.

Category	Terms	Effects		Immediate Loyalty	Monthly Loyalty	Cost	Requirements
Subject Integration	Integration Permitted	Overlord can use the Integrate Subject interaction		−50	−4	275	Ensured Sovereignty resolution enacted Subject:  Subsidiary or Tributary Bulwark Prospectorium Scholarium
	Integration Prohibited	Overlord cannot use the Integrate Subject interaction		+5	+0.5	0
Diplomatic Freedom	Limited Diplomacy	Subject cannot engage in diplomacy with other empires Subject cannot vote independently		−15	−1	100	A Voice for All resolution enacted Overlord:  Feudal Society  Franchising Subject:  Subsidiary or Tributary
	Restricted Voting	Subject can engage in diplomacy with other empires Subject cannot vote independently Subject joins any Federation the overlord joins Subject joins the Galactic Community if the overlord is part of it		0	0	25	Unless either Personal Oversight or A Voice for All resolution enacted: Subject:  Tributary  Genocidal
	Independent Diplomacy	Subject can engage in diplomacy with other empires Subject can vote independently		+5	+0.5	0	Personal Oversight resolution enacted
Expansion	Expansion Prohibited	Subject cannot construct starbases		−15	−1	100	Overlord:  Feudal Society  Franchising Subject:  Subsidiary or Tributary Bulwark Prospectorium Scholarium
	Expansion Regulated	Subject must pay the overlord an additional 50% of the  Influence cost to construct starbases		−5	0	50	Subject:  Tributary
	Expansion Permitted	Subject can construct starbases		+5	+0.5	0	Unless A Voice for All resolution enacted: Overlord:  Imperial Fiefdom overlord
Overlord Conflicts	None	The subject does not join the overlord's wars		0	0	0	Subject:  Subsidiary Bulwark
	Defensive	The subject joins the overlord's defensive wars		−10 if not  Pacifist −20 if  Pacifist	−1	50	Subject:  Tributary
	Offensive	The subject joins the overlord's offensive wars		−20 if not  Pacifist −40 if  Pacifist	−2	100	Subject:  Tributary
	All	The subject joins the overlord's wars		−30 if not  Pacifist −60 if  Pacifist	−3	150	Subject:  Tributary
Subject Conflicts	None	The overlord does not join the subject's wars		0	0	75	Overlord:  Feudal Society Subject:  Subsidiary or Tributary  Protectorate Scholarium
	Defensive	The overlord joins the subject's defensive wars		+5	+0.5	50
	Offensive	The overlord joins the subjects offensive wars		+10	+1	25	Subject:  Tributary  Protectorate Scholarium
	All	The overlord joins the subject's wars		+15	+1.5	0	Subject:  Tributary
Holdings Limit	0	The overlord cannot construct holdings on the subject's worlds		0	0	0
	1	The overlord can construct 1 holding on the subject's worlds		−5	−0.4	25	Subject:  Tributary
	2	The overlord can construct 2 holdings on the subject's worlds		−15	−1	75	Overlord DLC Subject:  Tributary
	3	The overlord can construct 3 holdings on the subject's worlds		−30	−2	150	Overlord DLC Personal Oversight resolution enacted Subject:  Tributary
	4	The overlord can construct 4 holdings on the subject's worlds		−50	−4	250	Overlord DLC Borderless Authority resolution enacted Subject:  Tributary
Sensors	Independent Sensors	Subject does not receive sensor data from the overlord		0	0	25	Borderless Authority resolution enacted Overlord:  Franchising
	Unified Sensors	Subject receives sensor data from the overlord		+5	+0.5	0	Unless Borderless Authority resolution enacted: Subject:  Tributary
Contribution	Basic	Basic Resources	Each contribution is adjustable in 15% increments as a proportion of the subject's income. Each contribution term can be up to -75% as a subsidy (to subject) or 75% as a tax (to overlord).	0 to −45	+3.7 to −3.7	0 to 225	Subsidiary or Tributary must pay at least 30% tax
	Advanced	Advanced Resources		0 to −45	+3.7 to −3.7	0 to 225	Subsidiary or Tributary cannot receive subsidy
	Research	Research		0 to −90	+3.7 to −3.7	0 to 225	Subsidiary or Tributary cannot receive subsidy
	Strategic	Strategic Resources		0 to −135	+3.7 to −3.7	0 to 225	Subsidiary or Tributary cannot receive subsidy

Subject types

There are 9 types of regular subjects and 3 types of specialized subjects.

Negotiable subjects

Type	Subject Requirements	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	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.

Non-negotiable subjects

Non-negotiable types of subjects cannot be proposed by regular empires. 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%
Satrapy	The Horde	Independent Diplomacy	Expansion Permitted	All	None	Basic 30%
Scion	Scion origin	Independent Diplomacy	Expansion Permitted	All	None	None

Specialized subjects

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 start as specialized subjects. Specialized subjects require less than 50% technological power difference between the overlord and themselves.

Overlord effects do not stack if there are multiple specialized subjects of the same type.

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% Defense armies from Relay Network: +2 Can construct Vigil Command holdings	Starbase	Damage	+50%	+50%	+75%
		Hull points	+50%	+50%	+75%
	Defense Platform	Damage	+50%	+75%	+100%
		Hull points	+50%	+75%	+100%
		Build cost	−25%	−50%	−75%
		Upkeep	−25%	−50%	−75%
		Cap	+2	+5	+8
	Owned Starbase Auras:	Shield hitpoints	+100%	+100%	+100%
		Hostile ship daily hull regen			−0.3% (−0.5% with Unyielding traditions completed)
	Monthly energy		−20%	−35%	−50%
	Monthly minerals		−20%	−35%	−50%
	Monthly food		−20%	−35%	−50%
	Admirals	Starting level		+1	+1
		Level cap		+2	+2
		Bulwark traits
		can be traded to the Overlord
	Technology	Unlocked	FTL Inhibition
		Added as research option	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 strategic resources
	Governors	Starting level		+1	+1
		Level cap		+2	+2
		Prospectorium traits
		can be traded to the Overlord
	Technology	Added as research option		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 ships	Build cost	+30%	+40%	+50%
		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: adds random research option instead of With  Discovery traditions completed: +3000 points of single type
	Scientists	Starting level		+1	+1
		Level cap		+2	+2
		Scholarium traits
		can be traded to the Overlord
	Can build Arctrellis science ships
Type	Effects for subject		Tier 1	Tier 2	Tier 3

Integration

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 control of all systems and ships to the overlord. All leaders, resources, and armies are removed, and new scientists will be required for the new science ships. 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.

Game concepts