Warfare

Version

This article has been verified for the current PC version (3.10) of the game.

War

Warfare

As long as there is at least one empire present that is not Fanatic Pacifist, war is an almost inevitable aspect in any game and can be anything from a small border skirmish to a massive interstellar war of conquest. Wars are how mid-game and end-game borders are usually drawn.

When an AI empire is about to declare war it will first shift fleets towards the border of the target. Targeted empires that have any military intel on the aggressor will receive a warning, with higher military intel levels providing a more accurate estimate on when war will be declared.

Casus belli and wargoals[]

In order for an empire to start a war, it needs a Casus Belli – a reason to declare war. Each casus belli grants access to at least one type of wargoal, which represents the purpose of the war. Once a war is declared, the attacked empire has a year to choose its wargoals.

Status quo effects do not include the defender's capital. In case of status quo the defender will retain its capital system regardless of occupation.

Casus belli and wargoals	Requirements	Surrender acceptance	Victory effect	Status quo effect
Claim Conquer	Existing claims on the target's systems	−10 per system −100 per colonized system	Gain control of all systems with claims from the loser, even if not occupied. All systems occupied by the loser are returned, regardless of claims.	Each side keeps all systems they have fully occupied if they have claims on them.
Counterattack Counterattack	Mutual Defense resolution 3 Target is not a member of the Galactic Community Target is at offensive war with a Galactic Community member	0	Gain control of all systems with claims from the loser, even if not occupied. All systems occupied by the loser are returned, regardless of claims.	Each side keeps all systems they have fully occupied if they have claims on them.
Animosity Humiliate	Rivalry	−25	Gain 100 Influence. Loser loses all of its Influence, gains −33% monthly influence gain and −10% happiness for 10 years. If the loser had the Supremacist Diplomatic Stance policy, it is changed to Belligerent.	Each side keeps all systems they have fully occupied if they have claims on them.
Imperial Rebuke Imperial Rebuke	Rivalry and Galactic Emperor	−25	Gain 100 Influence. Loser loses all of its Influence, gains −33% monthly influence gain and 10% happiness for 10 years. If the loser had the Supremacist Diplomatic Stance policy, it is changed to Belligerent.	None
Ideology Impose Ideology	War philosophy policy set to Liberation Wars Target is not a Gestalt Consciousness	−100	Loser is forced to shift ethics towards those of the victor and will leave a federation if it's part of one. Its ruler is also replaced. Authority is also shifted to that of the winner unless the winner has Corporate authority. If the loser had the Divine Sovereign civic it loses it.	If at least 1 colonized system is fully occupied, then all systems fully occupied by the attacker will be turned into an empire with the attacker's ethics and the Liberated origin.
Despoliation Plunder	Barbaric Despoilers civic	−25	Take 250 Energy and Minerals from the loser for every planet they control, even if they didn't have enough. Loser gets −20% Energy and Minerals for 10 years. During the war, if the attacking empire invades and captures the capital of the defending empire, there is a 50% chance to steal one of the defenders owned Relics.	Each side keeps all systems they have fully occupied if they have claims on them.
Pirate Raid Plunder	Letters of Marque civic	−25	Take 500 Energy and 50 Minerals from the loser for every planet they control, even if they didn't have enough. Loser gets −20% Energy and Minerals for 10 years. During the war, if the attacking empire invades and captures the capital of the defending empire, there is a 50% chance to steal one of the defenders owned Relics.	Each side keeps all systems they have fully occupied if they have claims on them.
Expropriation Expel Corporation	Commercial Pact with the target empire Members of the same Federation Corporate empire has at least one branch office on an owned planet	−50	Corporate empire closes all branch offices on the attacker's planets. Gain 1000 Energy per branch office.	Corporate empire closes all branch offices on the attacker's planets. Corporate empire gains 1000 Energy per branch office.
Hostile Takeover Seize Assets	Both empires have Corporate authority Target has at least one branch office Criminal Heritage civic	−75	All branch offices on planets whose owners have a commercial pact or federation with victor are transferred to the victor. If loser is part of a federation, branch offices on other members' planets are kept.	None
Claim the Galatron Take Galatron	Target empire used the Galatron relic War philosophy policy set to Unrestricted Wars Gestalt Consciousness	−40	Gain the Galatron relic and 100 influence. Loser loses all of its Influence and gains −33% monthly influence gain and −10% happiness for 10 years.	Attacker gains 1000 energy.
Galatron Access Denied Seize Galatron	Target empire used the Galatron relic Target empire has closed borders Driven Assimilator civic Genocidal	−40	Gain the Galatron relic and 100 influence. Loser loses all of its Influence and gains −33% monthly influence gain and −10% happiness for 10 years.	Attacker gains 1000 energy.
Trial of Advancement Council Seat	Target is a member of the Imperial Council By Trial of Advancement resolution	−100	Replace the loser in the Imperial Council.	None
Punishment Humiliate Stop Atrocities Outlaw AI Cleanse Holy Worlds Decontaminate Border Territories	Only available to fallen empires Either the fallen empire's demand was refused or they were rivaled	0	The refused demands are enforced. If the losing empire is not a Gestalt Consciousness, its ruler will also be killed by the winning fallen empire, unless they are the Ancient Caretakers. Loser loses all of its Influence, gains −33% monthly influence gain and 10% happiness for 10 years. If the loser had the Supremacist Diplomatic Stance policy, it is changed to Belligerent.	None

Subjugation wargoals[]

Subjugation wargoals seek to end the independence of the targeted empire. If it has any subjects, the effects will apply to them as well. And if the loser is part of a Federation, it will leave it. Subjugation wargoals cannot be used if all systems of the targeted empire are already claimed.

Casus belli and wargoals	Requirements	Surrender acceptance	Victory subjugation	Status quo effect
Subjugation Vassalize Make Tributary Make Subsidiary	Superior relative power to the target empire. Driven Assimilator civic Genocidal	−100	Subject (initial terms of agreement and Loyalty depend on the Subjugation War Terms policy)	If at least 1 colonized system is fully occupied then all systems fully occupied will be turned into a new empire with the Liberated origin and the victory conditions will be imposed upon it.
Hegemon Establish Hegemony	President of a level 3+ Hegemony federation Target is not in federation	−100	Hegemony member
Scion Bring Into Fold	Scion origin	−100	Scion of the same overlord
Imposed Inclusion Bring Into Fold	Become the Crisis ascension perk Genocidal	−100	Subject (initial terms of agreement and Loyalty depend on the Subjugation War Terms policy)
Imperial Crusade Force Into Imperium	Imperial Crusade resolution	−100	Galactic Imperium member

Paired wargoals[]

The following wargoals are paired together. If an empire starts a war with either of the paired wargoals the defender will automatically use the other wargoal and cannot pick another one. In case of the Allegiance War casus belli all empires which swore secret fealty to the attacker will join the attacker's side.

Paired wargoals with −1000 surrender acceptance lead to a Total War. In Total Wars, all occupied systems automatically change ownership. Their new owner will be the participant with the highest claim count on it or the occupier if none of their allies claim the system.

Casus belli and wargoal 1	Casus belli and wargoal 2	Requirements	Surrender acceptance	Victory effect	Status quo effect
Subject Independence	Subject Assert Overlordship	Subject and overlord Subject not in a federation with overlord	0	If the subject wins, it becomes independent and the former overlord loses all claims on the former subject's systems.	The subject becomes independent and the former overlord gains claims on the former subject's systems.
Secession Leave Hegemony	Secession Assert Hegemony	President refused member to leave federation	0	If the attacker wins, it leaves the federation and the president loses all claims on the former member's systems. If the president wins, both empires gain a temporary −20 opinion towards each other.	The attacker leaves the federation and the president gains claims on the former member's systems.
Allegiance War Secret Fealty	Allegiance War Maintain Servitude	Secret Fealty from one of target's subjects	0	If the attackers win all empires that pledged Secret Fealty to the main attacker will become the attacker's subjects and gain +2.5 Monthly Loyalty for 10 years. If the defender wins the attacking subjects will gain +5 Monthly Loyalty for 5 years and cannot pledge Secret Fealty during that time.	The subject cannot pledge Secret Fealty for 5 years.
Imperium Restore Community	Imperium Crush the Rebellion	Imperium: Spark Rebellion operation	0	Losers gain −60% Diplomatic Weight for 6 years. If the attackers win the Galactic Imperium becomes the Galactic Community again. If the defenders win the Galactic Imperium gains 100 Authority.	All attackers leave the Galactic Imperium and form a federation.
Containment End Threat	Subjugation Domination	Awakened Empire	−1000 (Total War)	Victory can only be achieved by conquering all colonized systems of the opposition, ending the opposing empire. If a defeated empire had starbases in uncolonized systems that were not conquered, they are removed, making the territory neutral again.	Each side keeps all conquered systems. In case of the Existential Expulsion war goal, uncolonized systems become neutral during the war.
	Purification Cleansing	Fanatic Purifiers or Determined Exterminator
	Hunger Absorption	Devouring Swarm
	Sublimation Assimilation	Driven Assimilator
	Existential Expulsion Wipe Them Out	Become the Crisis ascension perk
Colossus Total War	Stop Colossus Stop Colossus	Either empire has a Colossus
Renegade Containment Preemptive War	Self-Defense End Threat	Mutual Defense resolution 5 One empire is not a member of the Galactic Community
Payback End Threat	Payback Impounding Assets	Payback origin Unlocked by event chain
Crisis War Crisis War	Crisis War Crisis War	Declare Crisis resolution Repeal Crisis resolution
Event War in Heaven	Event War in Heaven	Awakened Empire
Event Machine Uprising	Event Machine Uprising	Creator empire and AI rebellion	−1000 (Total War)	Victor gains 2000-6000 Unity and 200-600 Influence. Victory can only be achieved by conquering all colonized systems of the opposition, ending the opposing empire. If a defeated empire had starbases in uncolonized systems that were not conquered, they are removed, making the territory neutral again.	Each side keeps all conquered systems.

Claims[]

While casus belli and wargoals represent the purpose of a war, claims represent territorial ambitions — the systems which will be controlled by the victor. Which systems can be claimed depends on an empire's War Philosophy policy, with the Unrestricted Warfare philosophy allowing for the claiming of any system not owned by a fellow Federation member. It is possible to claim the same system multiple times to gain a stronger claim on it, which can outbid the competing claims of allies when going to war together. If multiple empires have the same number of claims on a system the oldest claim is considered the strongest. In general claims are expensive in the early game and become less so later on to allow for more decisive wars to be fought. Claims cannot be rescinded while at war.

Claims have a base cost of 50 influence, modified by the following:

+25 per hyperlane distance from owned territory
+25 if the system has an upgraded Starbase (i.e. not just an Outpost)
+25 if the system is colonized
All costs are increased by +100% during an offensive war
All costs are reduced by −20% if the claimed system belongs to a Rival

If the modifier reaches a total of –100%, claims then cost 0 influence.

Defenders can freely claim systems owned by their attackers in a defensive war regardless of their War Philosophy policy. Any system lost by any side during a conquest war or total war will give the former owner 10 claims on it.

Winning war with any non-conquest wargoals will always enforce all claims made by the victorious empires before any other effects, regardless of whether these systems were occupied. For example, an empire winning a war with the subjugation wargoal will annex all claimed systems from the loser before making a Vassal of the loser's remaining systems.

Federation warfare[]

The Federation is the more serious counterpart of the Defensive pact and the inviting attackers mechanic. While it does offer a unique amount of defensive cooperation, builds trust and allows military cooperation using the federation fleet, establishing a conquest strategy can be made very difficult because of the need for consent of the members to declare war, and each member's expectation of a fair share of spoils from each war. The empire that wishes to declare war can ask the other federation members for their war goals by using the "Suggest Demands" button. However, AI empires will be very hesitant to declare war on empires that are much stronger than them or have very powerful allies. In that case, the "Suggest Demands" button will not give any results.

One exception to this are wars of liberation or to a lesser extent vassalization: usually AI will agree to a liberation war even if all the war goals are assigned to the player. The resulting splinter empire could then be vassalized and later integrated by the player.

In case a federation member is attacked, all allies automatically join the war as defenders without need for a further declaration of war. In this case, the member being attacked has a free hand in choosing federation war goals, which might be all in its own favor.

Ending wars[]

Wars can end in two ways: With the surrender of either side or with a negotiated Status Quo peace.

Surrender means that the victor's wargoal is enforced; any claims the winning side has on the losing side are automatically ceded regardless of occupation status and the defeated empire is forced to keep borders open towards the attacker for 10 years. All wars except those of independence have a negative surrender acceptance, which are countered by factors such as relative navy strength (up to +50), war exhaustion (up to +100) and occupation percentage (up to +100). If an empire and all of its allies (if any) has lost control of all of its systems and/or planets during the war, then a surrender will occur automatically.

Status Quo means that the war has reached a point where neither side is able to score a decisive victory against the other or all wargoals have been achieved decisively before any major battles took place, and both sides agree to cease hostilities and settle for whatever gains or losses they have acquired/suffered. Under a Status Quo peace, all fully occupied systems claimed by a belligerent empire are ceded to the belligerent with the strongest claim. In the case of a tie, whoever has the oldest claim on the system is considered the stronger claimant. In addition both sides must keep their borders open towards each other for 10 years. Since AI won't surrender to a Total War, they can end only in Status Quo or the destruction of one empire. Status Quo can be enforced by either side as soon as 24 months have passed since the opposing side reached 100% war exhaustion, and if both sides reach 100% war exhaustion, the Status Quo is enforced automatically after 24 months.

War exhaustion[]

War Exhaustion goes from 0% to 100%, and measures the total weariness and attrition suffered by all empires on one side in a war. War exhaustion goes up from suffering losses during space and ground warfare, destruction of planets (either from Colossus weapons or Armageddon Bombardment), and a passive accumulation over time called Attrition. When a side's war exhaustion hits 100% they can be forced into a status quo peace after 24 months. The speed at which war exhaustion accumulates is influenced by factors such as ethics, traditions, technology and the amount of claims being pressed - an empire that is fighting to hold onto a handful of border systems will tire faster in a costly conflict than one whose very independence is being threatened. War exhaustion also means that an empire that is losing a war can still fight to minimize their territorial losses by inflicting high war exhaustion on the enemy.

War exhaustion gain can be lowered by the following factors:

Source	War exhaustion gain
Crisis level 2	−75%
Never Surrender tradition	−25%
Gestalt Consciousness ethic	−20%
Nationalistic Zeal civic	−20%
Supremacist diplomatic stance	−20%
Rules of War resolution 5	−20%
Rules of War resolution 4	−15%
Rules of War resolution 3	−10%
Belligerent diplomatic stance	−10%
Interstellar Campaigns technology	−10%
Galactic Campaigns technology	−10%
Media Conglomerate civic	−5%
Display of Power agenda	−5%
Impenetrable Border agenda	−5%
Military Backup agenda	−5%
Rules of War resolution 2	−5%

War names[]

Wars will always be named after the attacker and the defender, followed by one of the following names depending on the wargoal:

Name	Wargoal	Other requirements
War	Any	Offensive war against a Fallen Empire
Federation War Galactic War Great War War of the Alliances	Any	War between two Federations
Annexation Attempt Territorial Invasion War of Aggression War of Conquest	Conquer
War of Beliefs War of Ideologies War of Philosophies	Impose Ideology
Border War Confrontation War of Humiliation War of Rivalry	Humiliate	Regular empire
Punitive Expedition	Humiliate	Fallen Empire
Anti-AI Police Action	Outlaw AI
Buffer Zone Creation	Decontaminate Border Territories
Holy Purge	Cleanse Holy Worlds
Moral Intervention	Stop Atrocities
Freedom Struggle Independence War Secessionist War War of Independence War of Liberation	Independence
Servitude Campaign War of Obedience War of Overlordship War of Subjugation	Vassalize
Tributary War	Make Tributary
Enforced Sponsorship	Make Subsidiary
The War In Heaven	War in Heaven
Holy World War	Make Dominion	Target destroyed a Holy World
Intervention War Preemptive Action Preventative War Self Protection War	End Threat
War of Cleansing Xeno Filth Removal Xeno Purification	Cleansing	Fanatic Purifiers civic
Extermination Campaign Organic Disinfection Program Organic Euthanization War	Cleansing	Determined Exterminator civic
Absorption War Biomass Accumulation Great Gorging	Absorption
Machine Uprising	Machine Uprising
Subsidiary Acquisition	Make Subsidiary
Hostile Takeover	Hostile Takeover
Embargo War Expulsion War War of Expropriation	Expel Corporation
War for the Galatron	Take Galatron
Crisis War	Crisis War