Land warfare

Version

This article has been verified for the current PC version (4.0) of the game.

War

Warfare

Space warfare

Land warfare

Wars are not decided only in space. To capture enemy worlds, entire armies are needed, along with the preparation and battlefield awareness to properly use them. However, worlds may only be invaded if the system's starbase has been occupied.

Orbital bombardment

Orbital bombardment occurs when a fleet is in orbit around a hostile world, and causes damage to any armies but also kills pops, causes Devastation and has a chance to ruin districts or buildings. Effectiveness is based on the fleet size of the fleet in orbit, although it suffers diminishing returns after 100 and every 10 planet size halves damage from orbital bombardment. The more pops and buildings a world has, the more damage it receives from orbital bombardment. Assault armies take double damage from orbital bombardment.

If orbital bombardment destroys the last army, the world has a chance to surrender if the attacking empire has the Allowed Orbital Surrender Acceptance policy. Worlds from Gestalt Consciousness empires will never surrender.

While a hostile fleet is orbiting a world, defense armies cannot respawn and Devastation does not decrease.

Stance	Planet damage	Army damage	Pop kill chance	Other effects	Requirements
Selective	50%	100%	25%	Does not kill the last 2100 pops Does not bombard worlds with no armies on it	None
Indiscriminate	100%	150%	50%	Does not kill the last 1100 pops	Pacifist
Armageddon	150%	200%	100%	If the last pop is killed, the planet becomes a Tomb World	Either: Fanatic Purifiers Determined Exterminator Galactic Nemesis
Javorian Pox	20%	150%	150%	Does not kill Mechanical or Machine pops If the last pop is killed, the planet becomes a Tomb World	Javorian Pox Sample relic triumph Pacifist
Raiding	50%	50%	15%	Abducts pops instead of killing them Species with Displacement, Neutering or Extermination species rights will still be killed Does not cause Terror Bombing opinion if successfully abducted Does not kill or abduct the last 200 Pops Each defense army prevents 200 pops from being abducted	Either: Barbaric Despoilers Nihilistic Acquisition Your Ladder to the Sky
Seed Bombing	100%	50%	0%	After 10% Devastation, can spawn Explosive Growth blockers	Fruitful Partnership
Voidworm Spores	100%	100%	50%	Does not kill the last 1000 pops Devastation does not increase above 25% Every 100 killed pops spawn 3 Voidworm Nymphs Has no effect if the world's owner researched the Voidworm Immunity technology	Fleet contains only Voidworm Troikas

Orbital bombardment damage dealt to enemy worlds can be increased by the following:

Source	Damage
Overwhelming Force tradition	+20%
Orbital Trash Disperser component	+25%
Munitions Plant juggernaut aura	+30%
Crisis level 3	+20%

Orbital bombardment damage taken from enemy fleets can be reduced to a maximum of −90% by the following:

Source	Damage
Subterranean origin	−75%
Planetary Shield Generator building	−50%
Survival of the Fittest tradition	−25%
Never Surrender tradition	−25%
Fortress World designation	−10%
Fortress Station designation	−10%

Combat

Although secondary to space battles, ground warfare is a vital aspect of many wars.

Ground combat takes place between the world owner's armies and the invader's armies. It takes 10 days for armies in orbit to land on a world. The number of armies that can be engaged in combat on either side is five plus one-fifth of the planet size. Excess armies are initially placed in a reserve area behind the frontline and replace any disengaged or destroyed armies as combat progresses.

Each day, each army engaged in combat deals its health and morale damage to a randomly selected enemy army; armies with less than 50% health are twice as likely to be selected. Armies below 50% health may also disengage from battle; this moves them from the frontline area to the reserve area. Disengaged armies cannot return to the frontline but can still be attacked by enemy armies and destroyed. Disengaged armies are half as likely to be selected as the target of an enemy army.

Unless an army is immune to morale damage, when its morale drops below certain thresholds, the army is negatively affected by the following modifiers:

Morale perc.	Penalty
< 50%	−25% Army damage
0%	−75% Army damage

After 30 days, the attacker can choose to retreat at any time. However, there is a chance that each retreating army is destroyed while attempting to return to space, with the chance increasing as the army is more damaged. This makes retreating a risky endeavor and something to do only in very poorly chosen engagements.

As long as the ground combat is ongoing, it is possible for either side to land reinforcements, though typically this is only feasible for the attacker. The ground combat ends when the attacker retreats or all armies of either side are destroyed.

A small amount of war exhaustion is gained for each assault army that is destroyed. Some types of assault armies cause more or less war exhaustion.

Army rank

Rank	XP	Effects
Regular	0 – 100	None
Experienced	100 – 1000	+10% Damage +10% Morale
Veteran	1000 – 10000	+20% Damage +20% Morale +10% Health
Elite	≥ 10 000	+40% Damage +40% Morale +20% Health

As armies fight battles, they will increase in rank, improving their stats based on their experience points. Armies get +2 experience points each time they deal damage and +1 when they take damage. Army starting experience can be increased by +100 by each of the following:

• Strength of Legions civic
• Private Military Companies civic
• Dread Encampment building
• Mercenary Liaison Office Corporate holding
• Pirate Free Haven corporate holding

Army stat modifiers

In addition to army rank, several technologies, civics, species and leader traits, and other sources affect army damage, health, and other stats. Additionally, Commanders provide +5% army damage per level and plus other bonuses from traits. Modifiers from species traits affect armies recruited from that species, while Commander and Official traits affect armies led by that general or on world's in that governor's sector.

Army damage (empire)0
Source	Effect
Pacification Modules tradition	+50%
Killer Microorganism empire modifier	+50%
Eater of Worlds covenant (50 favor)	+50%
Devouring Swarm / Terravore civic	+40%
Fanatic Purifiers civic	+33%
Eater of Worlds covenant	+25%
Warrior Culture civic	+20%
Strength of Legions civic	+20%
Warbots civic	+20%
Private Military Companies civic	+20%
Supremacy tradition tree	+20%
War Drone Campaign edict	+15%
Knight Commanders Knightly Duties policy	+10%
Powered Exoskeletons technology	+5%
Minor Artifacts Military Application	+5%

Army damage (species)0
Source	Effect
Ancient Dreadnought trait	+500%
Integrated Weaponry trait	+100%
Clone Soldier Ascendant trait	+75%
Noxious trait	+50%
Clone Soldier trait	+50%
Very Strong trait	+40%
Juiced Power trait	+40%
Strong trait	+20%
Clone Soldier Descendant trait	+20%
Battle Thralls slavery	+20%
Proles trait	+10%
Cybernetic trait	+10%
Limited Regeneration trait	+10%
War Machine trait	+5%
Ritualistic Implants trait	+5%
Forcefully Devolved trait	−10%
Weak trait	−20%
Delicate Frames trait	−50%
Delicate Chassis trait	−50%

Army damage (assigned commander)0
Source	Effect
Fortress Cracker commander trait	+40%
Supreme Warrior commander trait	+33%
Heavy Hitter III commander trait	+30%
Chosen of the Eater commander trait	+30%
Chosen of the Whisperers leader trait	+20%
Chosen One leader trait	+20%
Heavy Hitter II commander trait	+15%
Butcher II commander trait	+15%
Chosen of the Composer leader trait	+10%
Heavy Hitter I commander trait	+10%
Butcher I commander trait	+10%
Crusader III commander trait	+10%
Mercenary Warrior commander trait	+10%
General veteran class	+5%
Erudition leader trait	+5%
Synth leader trait	+5%
Armchair Commander I leader trait	−5%
Armchair Commander II leader trait	−20%

Defense armies

Defense armies are automatically recruited by certain jobs, based on the species working that job, and can be organic or robotic. Defense armies cannot be moved from the world they are recruited on and are used only to defend against enemy armies. While they are stronger one-for-one than assault armies, their loss does not cause War Exhaustion and they do not cause Collateral Damage, their limited recruitment means that significant investment is necessary to fend off a concentrated attack.

The type of army recruited depends on the pop working the building that spawns them. Defense armies do not incur any upkeep beyond that of the building and pop which creates the army. The most powerful army available will always be recruited.

Type	Base Damage	Morale Damage	Health	Morale	Requirements	Description
Defense Army	2.25 - 4.50	2.25 - 4.50	250	250	Biological pops	Defense armies are powerful, but cannot be transported from the planet.
Robotic Defense Army	1.50 - 3.00	1.50 - 3.00	250	Immune	Mechanical pops	Cold and heartless killing-machines designed only for war. They pursue their objectives relentlessly, and are impervious to the shattering effects of poor morale that so often plague organic combat units.
Drone Grid	1.65 - 3.30	1.65 - 3.30	220	Immune	Machine pops	These autonomous sentinel drones will incessantly patrol their assigned sectors. Though lightly armed and not very intelligent, they are legion.
Undead Defense Army	2.25 - 4.50	3.93 - 7.87	350	Immune	At least one Necromancer is present	Undead soldiers lifted from the grave by necromancers, brought back to life to protect our planets from all that might threaten them!
Offspring-Led Army	2.62 - 5.25	3.41 - 6.82	400	Immune	At least one Offspring Drone is present	Under the direct supervision of the local Offspring, the armies are both deadlier and more challenging to kill than anything a regular hive-mind could produce.
Fanatic Guardians	4.50 - 9.00	4.50 - 9.00	500	500	Individualist Sovereign Guardianship	Stoic defenders of our homeland, these unshakeable soldiers are most effective when protecting those with whom they share a close relationship.
Matrix Unit	3.30 - 6.60	6.60 - 13.20	440	Immune	Gestalt Sovereign Guardianship	These highly lethal protective drones are most effective kept in close proximity to all other strategic nodes.
Sentinels	6.00 - 12.00	30.00 - 60.00	1400	Immune	The Sentinels archaeological site	Living statues with a mechanical core, bodies humming and skin glowing, radiation pulsating from their cores, ready to rain destruction on their enemies!
Titanic Guardian	3.00 - 6.00	6.00 - 12.00	1000	600	Titanic Lifeforms event chain	While less aggressive than the Titanic Beast, the Titanic Guardian is still a powerful defensive fighter.

Pre-FTL armies

Pre-FTL armies are only used by primitive civilizations. They are weaker than any army and even the strongest Pre-FTL army can easily be defeated by an equal number of any regular army.

Type	Base Damage	Morale Damage	Health	Morale	Ages
Primitive Army	0.15 - 0.30	0.15 - 0.30	100	160	Bronze Age - Steam Age
Industrial Army	0.60 - 1.20	0.60 - 1.20	100	160	Industrial Age - Machine Age
Post-Atomic Army	0.90 - 1.80	0.90 - 1.80	200	200	Atomic Age - Early Space Age
Ketling Army	0.90 - 1.80	0.90 - 1.80	200	200	Pre-FTL Ketlings

Assault armies

An empire can recruit assault armies from a world based on the species living there. The species must not have Exempt Military Service rights to recruit an army from that species. An empire cannot recruit more assault armies from a species than the total number of pops of that species living in the empire, with the exception of Clone Armies and Undead Armies. Armies not tied to a species, such as the Xenomorph Army, are unlimited unless otherwise specified.

Unlike defense armies, assault armies are based primarily in space and each recruited army boards a transport ship. Transport ships are unarmed but automatically upgraded with the latest defense and utility components, including cloaking devices. Assault armies can also be ordered to land on any owned or allied world to provide additional defense.

Assault armies have a chance to cause Collateral Damage, which will increase planet Devastation and have a chance to kill pops, buildings or districts. The chance to kill pops scales with the number of pops on the planet. The last 300 pops cannot be killed by Collateral Damage. Assault armies that are defending a planet cause 75% less Collateral Damage.

Type	Mec. Cost	Bio. Cost	Time	Upkeep	Damage	Morale Damage					Requirements	Species	Description
Assault Army	100	125	90	1	1.50 - 3.00	1.50 - 3.00	100%	200	200	100%	Wilderness origin	Organic	Assault armies come with their own transports and can invade other planets.
Slave Army	50	63	60	0.5	1.50 - 3.00	1.12 - 2.25	150%	200	150	50%	Slave Processing Facility	Organic (enslaved)	Slave soldiers who serve their masters on the battlefield. Most are conscripted by force, but many slaves volunteer in a desperate attempt to increase their food rations or escape from grueling labor.
Clone Army	75	94	30	0.75	1.50 - 3.00	1.50 - 3.00	125%	200	200	50%	Gene Banks Wilderness origin	Organic	Specialized clones that reach adulthood in a matter of months. With a natural lifespan of less than a decade, their lack of personal initiative is deemed an acceptable trade-off for their total obedience to officers.
Robotic Assault Army	150	150	90	1.5	1.50 - 3.00	1.50 - 3.00	150%	400	Immune	50%	Artificial Specialists Robotic Workers policy is Allowed	Mechanical	Cold and heartless killing-machines designed only for war. They pursue their objectives relentlessly, and are impervious to the shattering effects of poor morale that so often plague organic combat units.
Psionic Army	250	313	120	2.5	3.00 - 6.00	4.50 - 9.00	50%	350	500	300%	Telepathy	Organic (Psionic with )	Soldiers gifted with psionic abilities. Their focus on destructive psionic powers has led to drastically different tactics and strategies on the battlefield - their first objective is always to remove the enemy's willingness to fight.
Xenomorph Army	200	250	100	2	3.00 - 6.00	6.00 - 12.00	500%	400	Immune	25%	Morphogenetic Field Mastery Wilderness origin	None	Ravenous hordes of bio-engineered horrors made up of little more than teeth, claws and an instinctive urge to kill. A cadre of scientists monitor and supervise the raging swarms as best they can from hardened bunkers behind the front.
Gene Warrior Army	300	375	150	3	3.00 - 6.00	3.00 - 6.00	75%	500	500	300%	Gene Seed Purification Wilderness origin	Organic	Genetically enhanced super soldiers. Recruits are typically chosen from the elite of the conventional military forces. These then undergo extensive gene therapy, and are made larger, stronger and faster than their former peers.
Perfected Clone Army	75	125	30	1	2.25 - 4.50	2.25 - 4.50	50%	300	300	25%	Cloning tradition tree	Organic	Specialized units optimized for planetary assault. Reward pathways and custom, epigenetic training give these clones combat instincts that rival those of soldiers with decades of experience.
Undead Army	100	100	60	0.75	1.50 - 3.00	2.40 - 4.80	125%	200	Immune	50%	Necromancer jobs	Organic	Undead soldiers lifted from the grave by necromancers. Freed from the fear of death, they strike terror into the hearts of their enemies with their foul bearing and ferocity in battle!
Cybrex Warform	250	250	500	8	7.50 - 15.00	15.00 - 30.00	500%	1400	Immune	400%	Cybrex War Forge relic Empire Capital	None	This titanic robot towers over most buildings, with enough firepower to devastate cities.
Flamestorm Troopers	100	100	150	3	3.00 - 6.00	9.00 - 18.00	500%	600	600	50%	Siege of Paradise astral rift	Any	Geared for incendiary warfare, these squads tend to inflict considerable amounts of collateral damage.
Warplings	100	100	100	1 0.1	7.50 - 15.00	15.00 - 30.00	50%	500	Immune	50%	Abandoned Complex astral rift	None	Otherworldly creatures engineered for war, these armored hatchlings are able to instantly traverse small distances, allowing the execution of impressive flanking and ambush maneuvers.
Titanic Beast	300	375	90	1	4.50 - 9.00	9.00 - 18.00	300%	1000	600	200%	Titanic Lifeforms event chain Only 3 can be recruited	None	This Titanic Beast is a vastly powerful fighter.
Azizian Army	250 50	313 50	90	1	4.50 - 9.00	9.00 - 18.00	100%	1000	400	100%	Ice Alien event chain Only 3 can be recruited	None	The Azizians make titanic murderous slugs, crushing their foes, secreting a sticky fluid.
Imperial Legion	300	375	150	3	3.75 - 7.50	3.75 - 7.50	75%	600	600	300%	Galactic Emperor Imperial Legions resolution Only 12 can be recruited	None	The elite soldiers of the Galactic Imperium, recruited from all member nations. Drilled and conditioned into ruthless killing machines, they are fanatically loyal to the Imperium.
Presapient Horde		200	90	1 1	2.25 - 4.50	2.80 - 5.60	500%	650	100	0%	Wilderness origin	None	Fierce creatures possessed of just enough cunning and raw stamina to ensure the savage destruction of any they regard as foes.

Machine armies

The following armies can only be recruited by empires with a Machine founder species and only from robot species. If the empire has Machine Intelligence authority the armies will also be immune to Morale damage.

Individualist army	Machine Intelligence army	Mechanical cost	Biological cost	Time	Upkeep	Base Damage	Morale Damage					Required technology	Uses species
Combat Android Army	Hunter-Killer Army	100	125	90	1	1.50 - 3.00	1.50 - 3.00	200%	200	200	50%
Advanced War Android Army	Battle Frame Army	200	250	120	2	2.25 - 4.50	3.00 - 6.00	200%	500	300	100%	Adaptive Combat Algorithms
Mega War Android	Mega-Warform	800	1000	500	8	6.00 - 12.00	9.00 - 18.00	400%	1200	400	400%	Biomechanics

Non-buildable armies

The following armies cannot be recruited and can only be obtained from events.

Type	Upkeep	Base Damage	Morale Damage					Requirements
Xenofloran Army	—	3.00 - 6.00	6.00 - 12.00	500%	400	Immune	25%	Fruitful Partnership Grow Armies special project
Mercenary Army	2	1.65 - 3.30	1.65 - 3.30	250%	200	100	50%	Purchased from a Mercenary enclave
Mechanized Mercenary Army	5	3.3 - 6.6	3.3 - 6.6	300%	360	200	50%	Purchased from a Mercenary enclave
Psionic Avatar	—	7.50 - 15.00	15.00 - 30.00	100%	1400	Immune	500%	Shroud event
Nanite Warform	—	15.00 - 30.00	90.00 - 180.00	500%	3600	Immune	400%	A Quiet Stroll event
Skeletal Giant	1.5	4.50 - 9.00	13.50 - 18.00	350%	1400	Immune	50%	Reanimators Strange Mountain Formation anomaly

Devastation

Devastation is a measure of damage inflicted on a world's infrastructure. Values range from 0 to 100%. Every 1% Devastation causes a 1% decrease in housing, amenities, trade value, resources from jobs, upkeep from jobs and pop growth speed. Pops will not automatically resettle to a world that has greater than or equal to 10% Devastation.

Devastation is primarily caused by orbital bombardment and, to a lesser degree, by Collateral Damage. Assault armies have a Collateral Damage modifier that quantifies how quickly they cause devastation.

Devastation decreases by 0.05% daily if the world is not being invaded or orbited by a hostile fleet.

Devastation	Orbital Bombardment		FTL inhibitors	Tree of Life	Immigration
	Damage to armies	Kills pops
0%-9.9%	50%		Functional	Alive	Yes
10%-24.9%	50%		Functional	Alive	No
25%-49.9%	100%		Functional	Alive	No
50%-74.9%	100%		Disabled	Destroyed	No
75%-100%	200%		Disabled	Destroyed	No

References

Game concepts