Megastructures

Version

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

Stellaris_Megastructure_Tier_List — Stellaris Megastructure Tier List

Megastructures are colossal constructions. Expensive and time-consuming to build or repair, these remarkable feats of engineering are nonetheless important wonders that provide large bonuses, demonstrating the technological and economic primacy of the builders' empire. They cannot be built in orbit of a celestial body that has an uninvestigated anomaly. All megastructures except Gateways are destroyed if a Star-Eater destroys the system.

Construction[]

A construction ship is required to build the first stage (construction site) of any megastructure. If it has multiple stages, the following stages do not require a construction ship. All megastructures have a different texture depending on the empire that built or repaired them.

A few bonuses affect megastructure construction speed. These are highly desirable considering the great time requirements of such projects:

Master Builders ascension perk increases the build speed by +50%
Living Metal Mega-Construction edict increases the build speed by +50%
Architectural Renaissance unity ambition also increases the build speed by +50%
The Isolated Contingency Core relic triumph increases the build speed by +300% for 10 years

FTL megastructures[]

FTL megastructures can only be constructed at the edge of a system and allow fleets to traverse to an identical megastructure, greatly easing travel across the galaxy. They work together with the FTL megastructures of another empire unless borders are closed or the empires are at war with each other. FTL megastructures can be constructed in any system which doesn't already have that type of megastructure. Unlike other megastructures, they can be constructed in the systems of subjects as well.

Gateways[]

While exploring the galaxy, empires may find abandoned gateways that were once part of a massive, galaxy-spanning network. The number of abandoned gateways can be scaled by galaxy settings.^[1]

Once an abandoned gateway is discovered, the Gateway Activation technology can appear, which allows abandoned gateways to be repaired. Repairing an abandoned gateway takes 2 years and costs 6000 energy and 2500 alloys. When a gateway is reactivated for the first time in the galaxy, another random gateway is also reactivated along with it.

Once the Gateway Activation technology is researched, the Gateway Construction technology can appear, which allows new gateways to be constructed. The construction site is built in 3 years and costs 75 influence and 2500 alloys. Upgrading it into a fully functional Gateway takes 3 years and costs 6000 energy and 2500 alloys.

Gateways allow travel to any other gateway instantly, so long as the borders are open and the destination is not controlled by an enemy empire. As a bypass, Gateways generally act like a hyperlane connection between systems, such that claims and trade can be extended through them, however sectors don't extend through gateways.

L-Gates are a special type of gateway, which have a separate network from regular gateways. Instead of jumping from any to any, L-Gates all jump to the Terminal Egress system in the L-Cluster, then from there to any other L-Gate so long as its borders are open, or you are at war. L-Gates are opened through a special project, and new L-Gates cannot be constructed.

Hyper Relays[]

Hyper Relays can be constructed once the Hyper Relays technology is researched and allow ships to jump to Hyper Relays in adjacent systems instead of using the existing hyperlane connections, thereby avoiding having to traverse systems at sublight speeds. They are constructed directly in a single stage, taking one year and costing 25 influence, 500 alloys, and 100 rare crystals. Hyper Relay links are shown on the galaxy map as a thicker hyperlane. Potential (inactive) links are shown as yellow connections on the galaxy map. A link may be inactive because of closed borders, war, or if the relay is ruined. A ruined Hyper Relay can be restored for 500 energy, 500 alloys, and 100 rare crystals, taking 6 months to complete.

Hyper Relays can grant additional effects based on edicts and subject specializations. Hyper Relay edicts require the empire's capital system to be part of the network, while the benefits granted by subject specializations require a connection between the overlord's capital and the subject's capital. Subjects do not benefit from their overlord's network effects.

Hyper Relays can be built from the galaxy view, which places them semi-randomly within the system. In systems with wormholes or existing gateways, it is recommended to instead go into the system view to manually place the Hyper Relay near to the wormhole or gateway to better facilitate travel. However, Hyper Relays cannot connect through wormholes or gateways.

Habitats[]

Mammalian Habitat — Mammalian habitat central complex

Habitats are colonizable megastructures that can be built above stars and planets and are finished in a single stage. Each system can only have one habitat and they cannot be built in systems with a ringworld. Building a Habitat Central Complex costs 200 Influence and 1500 Alloys and takes 60 months to construct. The habitat still requires colonization but the colony develops twice as fast as on planets.

Once the Habitat Central Complex has been constructed, orbitals can be constructed in the system. Orbitals are stations that increase the building slots and/or max districts of the Habitat Central Complex. When orbitals are reduced to 5% Hull Points, they are disabled and the Habitat Central Complex gains 10 Devastation and a blocker.

Minor Orbitals cost 50 alloys and take 6 months to construct. They can only be constructed in the orbit of moons and asteroids. If disabled, the Habitat Central Complex gains a Ruined Minor Orbital blocker.
Major Orbitals cost 200 alloys and take 24 months to construct. They can only be constructed in the orbit of stars and planets. If disabled, the Habitat Central Complex gains a Ruined Major Orbital blocker. Major Orbitals increase the district capacity of the Habitat Central Complex in addition to their other effects.
Demesne Orbitals cost 200 alloys, take 24 months to construct and can only be constructed by empires with the Knights of the Toxic God origin that have the Maw of the Toxic Entity relic. They can only be constructed in the orbit of stars and planets. If disabled, the Habitat Central Complex gains a Ruined Major Orbital blocker. Demesne Orbitals increase the district capacity of the Habitat Central Complex and give it an additional Knight job.

Habitats have a unique set of districts distinct from normal planetary ones. Habitation districts and industrial districts are only limited by district cap but other districts require either the Habitat Central Complex or its orbitals to be built over a resource deposit. An orbital built around a body with no deposit provides +0.5 building slots.

If either the Habitat Central Complex or an orbital is built above a celestial body with an advanced or strategic resource, the habitat gains a planetary feature that exploits the resource. If the celestial body already had a mining or research station, the habitat or orbital replaces it.

Only Gestalt Consciousness empires, Void Dwellers, or empires with the Voidborne ascension perk can construct housing buildings on Habitats.

Habitats have a planet size of 6. They are shown in one of three tiers shown in the outliner, depending on the level of the capital building.

Tier	Habitability	Building Slots per Orbital	Max Districts per Major Orbital	Branch Office Building Slots	Required technology	Required pops
I (Habitat Administration)	40	0.5	0.5	1	Orbital Habitats	0
II (Expanded Central Control)	50	0.75	0.75	2	Habitat Expansion	10
III (Advanced System Control)	60	1	1	3	Advanced Space Habitation	25

Habitats can be obtained the following way:

If the Utopia DLC is enabled, any empire can research the technologies to construct and upgrade habitats.
Empires with the Void Dwellers origin start with a habitat and the technology to build more. They can research the technology to upgrade them from the start.
Empires with the Knights of the Toxic God origin start with a habitat. They can research the technology to build more from the start but cannot research the technology to upgrade them without the Utopia DLC.
Empires with the Payback origin can gain a unique size 10 habitat called Recovered Asset as one of their two choices following the conclusion of the The Aftermath of Battle archaeological site. Choosing the habitat unlocks the technology to build more.
If the Apocalypse DLC is enabled, empires created by the Horde breaking up start with the technology to construct habitats. These habitats can be captured by other empires.
If the First Contact DLC is enabled, the Ithome cluster has a 25% chance to spawn. The Ithome's Gate system contains 3 habitats. The system cannot support orbitals but each habitat has a unique modifier granting it max Habitability and Building Slots.
A system called Federation's End can randomly spawn and contains 2 mammalian habitats. The system does not require any DLC to spawn but is too empty to support orbitals.

Habitat Central Complexes can be ruined by a Colossus or crises. If ruined, all orbitals are destroyed.

Orbital Rings[]

Orbital ring trailer — Mammalian orbital ring with shipyard module

Half megastructure and half starbase, Orbital Rings can be built around colonized planets to act as an additional starbase or provide useful bonuses for the planet below. They do not require a construction site and are finished in a single stage by the construction ship. Orbital rings also have +100% fire rate.

Tier	Cost	Upkeep	Modules	Buildings	Platforms	Hull	Armor	Weapons range	Weapons	Utilities	Requirements
1	1000 50 720	2	2	0	2	5000	1000	+100%	1 3	2 1	Orbital Rings technology
2	1500 100 900	3	3	1	4	10000	2000	+150%	2 6	4 1	Star Fortress technology Planet has either: Capital tier 2 or Planetary Ascension tier 3
3	2000 150 1080	4	4	2	6	20000	2000	+200%	3 9	6 1	Citadel technology Planet has either: Capital tier 3 or Planetary Ascension tier 5

Modules[]

Orbital Rings use their own set of modules, which are mostly similar to Starbase modules except that they do not interact with trade routes in any way. An Orbital Assembly Complex Holding provides additional bonuses to each module.

Module	Cost	Upkeep	Effects	Required technology	Description
Orbital Shipyard	50 180	1	+1 Shipyard Capacity +1 Shipyard Capacity with Orbital Assembly Complex on planet		A Shipyard may build one ship at a time, in parallel with other Shipyards.
Orbital Anchorage	50 180	1	+4 Naval capacity +2 Naval capacity with Naval Logistics Office +2 Naval capacity with Orbital Assembly Complex on planet		Fleet anchorages are necessary to support the growth of our navy.
Planetary Defense Guns	50 180	1	+2 Medium weapon components +20% Starbase armor hit points +20% Starbase hull points +1 Defense platform cap +1 Defense platform cap with Orbital Assembly Complex on planet		Adds two medium-size weapon slots to the Orbital Ring.
Habitation Module	200 25 360	2	+1 Max districts for orbited planet +0.5 Building slots with Orbital Assembly Complex on planet	Anti-Gravity Engineering	High-speed space elevators allow the planet to extend its habitation, resource storage and refinement facilities into orbit.
Planetary Defense Batteries	50 180	1	+2 Guided weapon components +20% Starbase armor hit points +20% Starbase hull points +1 Defense platform cap +1 Defense platform cap with Orbital Assembly Complex on planet	Space Torpedoes	Adds two missile weapon slots to the Orbital Ring.
Planetary Defense Hangars	50 180	1	+1 Hangar weapon components +20% Starbase armor hit points +20% Starbase hull points +1 Defense platform cap +1 Defense platform cap with Orbital Assembly Complex on planet	Carrier Operations	Adds a hangar for Strike Craft to the Orbital Ring.

Buildings[]

In addition to most of the regular starbase buildings, Orbital Rings can construct a set of buildings that improve the planet's output. All of them take one year to build.

Building	Cost	Upkeep	Planet effects	Requirements	Description
Climate Optimization Stations	100 100	2 1	+2 Food from Farmer category jobs	Advanced Food Processing technology	Detailed monitoring of local conditions means we can influence the planet's climate at a regional level, increasing agricultural yields.
Low Gravity Mega-Refiners	100 100	2 1	+2 Minerals from Miner category jobs	Advanced Mineral Purification technology	Centralizing mineral refining operations on the Orbital Ring allows for novel techniques that increase mining efficiency.
Stratospheric Ionization Elements	100 100	2 1	+2 Energy Credits from Technician category jobs	Planetary Power Grid technology	These devices dramatically reduce power loss during distribution, increasing overall generator output.
The Giga-Mall	100 100	2 1	+1 Amenities from Clerks +5% Trade Value	Interstellar Economics technology	Moving all shopping and trade facilities to the Orbital Ring means our Clerks can facilitate more business, more effectively than ever before.
Alloy Processing Facilities	200 300	5 2	+1 Alloys from Metallurgist category jobs −2 Minerals from Metallurgist category jobs If Catalytic Processing, −3 Food from Metallurgist category jobs instead	Nano-Separators technology	Alloys from the surface are further processed in orbit, creating usable materials from what would otherwise be wasted by-products.
Orbital Logistics Systems	200 300	5 2	+1 Consumer Goods from Artisan category jobs −1 Minerals from Artisan category jobs	Replicator Kiosks technology	Transferring logistics operations to automated systems on the Orbital Ring allows planetside Factories to run continuously at full speed.
Orbital Filing System	200 300	2 1	+1 Unity from Administrator, Manager, Priest, and Telepath category jobs	Effective Bureaucracy technology	Efficiency and progress can be ours once more, now that our Administrators have near instant access to the paperwork that defines their lives.
Synaptic Relays	200 300	2 1	+1 Unity from Synapse Drones	Clustered Synapses technology	Portions of the Orbital Ring have been modified to enhance synaptic signals, improving control over drones on the surface.
Orbital Maintenance Drops	200 300	2 1	+1 Amenities from Maintenance Drones	Resource Processing Algorithms technology	Prepackaged pods of maintenance material - and the drones necessary to distribute them - can be dropped from orbit anywhere they are needed, at a moment's notice.
Orbital Garden	50 50	1 1	+1 Food from Farmer category jobs Non-hostile space fauna are attracted and collect Seed Pods Relic-spawned Prethoryn fleets collect Seed Pods if in orbit	Fruitful Partnership	A vacuum garden for our Orbital Ring, blooming with genetically enhanced plantlife designed to attract spaceborne fauna.

Planetary building replacements[]

The following orbital ring buildings fulfill the same function as certain planet buildings. They have the same requirements to construct and cannot be built if the matching building has been constructed on the planet.

Building	Cost	Upkeep	Planet effects	Replaced building	Requirements	Description
Noble Estates	200 300	5 2	+2 Noble jobs +2 Housing	Noble Estates	Aristocratic Elite civic Thrall World designation on orbited planet	Magnificent structures that take advantage of reduced gravitational effect in orbit house the local nobility. Significant portions of the ring are dedicated to their every whim.
Orbital Psi Corps	200 300	5 2	+2 Telepath jobs +5 Stability	Psi Corps	Psi Corps tradition Resort World designation on orbited planet Thrall World designation on orbited planet	A segment of the Orbital Ring is devoted to training psi-gifted individuals, allowing the Psi Corps to keep a watchful eye on the planet below. The Psi Corps is your friend. Trust the Corps.
Orbital Shield Generator	200 300	5 2	+25% Shield Hit Points +25% Defense Platform Shield Hit Points	Planetary Shield Generator	Planetary Shields technology	Hardening the shields of the orbital defenses will interfere with any planetary shields, but will allow them to hold off against more powerful weapons.
Orbital Stock Exchange	200 300	5 2	+2 Merchant jobs +20% Trade Value	Galactic Stock Exchange	Galactic Markets technology Resort World designation on orbited planet Thrall World designation on orbited planet	By engaging in free trade of goods and services we allow for a more specialized economy, where an individual can excel in a narrow field and trade for their needs.
Orbital Slave Processing Hub	200 300	5 2	+5% Slave Pop Resource Output −25% Slaves Political Power −50% Automatic Resettlement Chance Unemployed Slaves automatically resettle Permits recruiting Slave Armies	Slave Processing Facility	Neural Implants technology Allowed Slavery policy Resort World designation on orbited planet	An orbital facility used to process slave labor for the planet below. Those that have been processed have any trace of free will extinguished.
Orbital Embassy Complex	200 300	5 2	+2 Politician jobs +2 Available Envoys	Embassy Complex Grand Embassy Complex	Xeno Relations technology Orbiting the Empire Capital Resort World designation on orbited planet Thrall World designation on orbited planet	This orbital complex is intended to awe the viewer, rendering them more compliant in negotiations. Due to the need to be close to the seat of the government, it can only be built in orbit of our capital.

Multi-stage megastructures[]

Multi-stage megastructures are constructed in multiple stages that require the technology of the same name before they can be constructed. Empires lacking the technology can make use of a multi-stage megastructure which they conquered from another empire, but they cannot upgrade it before they research the technology.

Multi-stage megastructures start with a construction site that provides no benefit. However, each subsequent construction phase brings increasing bonuses, culminating with the end of the megastructure construction.

Only one multi-stage megastructure may be built in each system. Multi-stage megastructures must be built either over an uninhabitable planet or a star. There must not be an anomaly present on the planet or star, but an anomaly on another planet or star in the system does not block construction.

It is only possible to build, upgrade, or restore one multi-stage megastructure at a time. The limit can be increased by +1 with each of the following:

Master Builders ascension perk
Architectural Renaissance ambition edict
Level 5 Research Cooperative president

Apart from the Ring World and Quantum Catapult, each multi-stage megastructure can only be built once per empire, or twice if the empire has the Isolated Contingency Core relic, and cannot be rebuilt if the existing one is lost or destroyed. However, multi-stage megastructures obtained through conquest and ruined ones that were found in the galaxy and repaired do not count against this limit. A conquered incomplete megastructure can still be upgraded as long as the new owner has the prerequisite technology.

Ring Worlds can have their habitable segments destroyed by a Colossus as well as by Crisis factions and cannot be repaired again. All multi-stage megastructures are permanently ruined if the system is destroyed by a Star Eater.

Megastructure	Stage	Production	Upkeep	Time	Cost	Notes
Science Nexus	Site	None	−25	5 years	5000 5000	Owning a Science Nexus may trigger the Fountain of Youth event chain
	Stage I (Hub)	+100 Research +5% Research Speed	−50	10 years	5000 15000
	Stage II (Research Wings)	+200 Research +10% Research Speed	−75	10 years	5000 15000
	Stage III (Completed)	+300 Research +15% Research Speed	−100	10 years	5000 15000
Sentry Array	Site	None	−20	5 years	2500 5000	Until finished, the Sentry Array cannot see through nebulae As no system will have low intel level, a completed Sentry Array will prevent space creatures from respawning
	Stage I (Sentry Hub)	+20 Hyperlane Scanner Range +10 Base intel level	−40	5 years	2500 10000
	Stage II (Sentry Spire)	+40 Hyperlane Scanner Range +20 Base intel level	−60	5 years	2500 10000
	Stage III (Sentry Aerials)	+60 Hyperlane Scanner Range +30 Base intel level	−80	5 years	2500 10000
	Stage IV (Completed)	Entire Galaxy Hyperlane Scanner Range +40 Base intel level	−100	5 years	2500 10000
Mega Art Installation	Site	None	−5	5 years	2500 5000	The final stage requires the Ancient Relics DLC A ruined Mega Art Installation is repaired to stage 3, and can be upgraded to stage 4 as with the constructed version
	Stage I (Nascency)	+100 Unity +5% Amenities	−10	10 years	2500 15000
	Stage II (Maturity)	+200 Unity +10% Amenities	−20	10 years	2500 15000
	Stage III (Completed)	+300 Unity +15% Amenities	−30	10 years	2500 15000
	Stage IV (Perfection)	+400 Unity +20% Amenities	−30	10 years	2500 2000
Strategic Coordination Center	Site	None	−5	5 years	2500 5000
	Stage I (Hull)	+50 Naval capacity +2 Starbase capacity +4 Defense Platforms +5% Sublight speed	−25	10 years	2500 15000
	Stage II (Comms)	+100 Naval capacity +4 Starbase capacity +8 Defense Platforms +10% Sublight speed	−50	10 years	2500 15000
	Stage III (Completed)	+150 Naval capacity +6 Starbase capacity +12 Defense Platforms +15% Sublight speed	−75	10 years	2500 15000
Interstellar Assembly	Site	None	−5	5 years	2500 5000
	Stage I (Locus)	+10% Diplomatic weight +15 Opinion from all empires	−10	5 years	2500 10000
	Stage II (Consul Ring)	+20% Diplomatic weight +30 Opinion from all empires +1 Available envoys	−20	5 years	2500 10000
	Stage III (Forum Modules)	+30% Diplomatic weight +75 Opinion from all empires +1 Available envoys	−30	5 years	2500 10000
	Stage IV (Completed)	+40% Diplomatic weight +150 Opinion from all empires +2 Available envoys	−40	5 years	2500 10000
Mega Shipyard	Site	None	−5	5 years	2500 3000	All ships start with 100 experience Can only be built around stars, in one-star systems
	Stage I (Framework)	+5 Shipyard Capacity +33% Empire Ship Build Speed	−10	5 years	2500 10000
	Stage II (Core)	+10 Shipyard Capacity +66% Empire Ship Build Speed	−20	5 years	2500 10000
	Stage III (Complete)	+20 Shipyard Capacity +100% Empire Ship Build Speed Titan and colossal ship construction	−40	5 years	2500 10000
Quantum Catapult	Site	None	−25	5 years	300 2000	Can only be constructed around pulsars and neutron stars (including in binary or trinary systems) The accuracy of the catapult decreases with distance and is increased by upgrading the megastructure Catapulted fleets gain +33% Fire Rate for 120 days (+50% with Slingshot to the Stars origin) Quantum Catapult technology is required to use it, merely controlling it is not enough Hyper Relays technology is required for the MIA time reduction to apply If Astral Planes is installed the effects of the catapult can be upgraded by the Astral Calibration astral action
	Stage I (4 lenses)	Can catapult fleets in the system −10% Missing in Action time	−50	5 years	3000
	Stage II (8 lenses)	Can catapult fleets in the system −25% Catapult windup time −20% Missing in Action time +30% Catapult Accuracy +50% Catapult Range	−60	5 years	3000
	Stage III (Complete)	Can catapult fleets in the system −50% Catapult windup time −30% Missing in Action time +50% Catapult Accuracy +150% Catapult Range	−75	5 years	10000
	Stage I (Repaired)	Can catapult fleets in the system −30% Catapult windup time −20% Missing in Action time +30% Catapult Accuracy +50% Catapult Range	−30	10 years	2500	Must be restored from the ruined catapult spawned by the Slingshot to the Stars origin Any Slingshot to the Stars empire can restore the special catapult without Mega-Engineering, but requires that technology to improve the catapult; restoring the catapult also unlocks the Quantum Catapult technology. Other empires can restore the special catapult with Mega-Engineering
	Stage II (Improved)	Can catapult fleets in the system −50% Catapult windup time −30% Missing in Action time +50% Catapult Accuracy +150% Catapult Range	−50	10 years	10000

Galactic Wonders[]

Galactic wonders are very powerful megastructures that require the Galactic Wonders ascension perk to gain the technology to construct them.

Megastructure	Stage	Production	Upkeep	Time	Cost	Notes
Ring World	Site	None	−5	5 years	300 5000	Cannot be built around a black hole, or in systems with multiple stars or without planets or asteroids Cannot be built if there are habitable planets, including habitats, present All habitable segments feature 100% habitability for all species, can build up to 10 unique districts, and have their own unique designations Upon completion of the frame, all planets are removed from the system Multiple segments can be built at the same time if the empire has the capacity to work on more than one megastructure simultaneously Habitable segments require colonization
	Stage I (Frame)	None	None	13.3 years	10000
	Stage II (1 Segment)	+1 Habitable Segment	None	10 years	10000
	Stage III (2 Segments)	+2 Habitable Segments	None	10 years	10000
	Stage IV (3 Segments)	+3 Habitable Segments	None	10 years	10000
	Stage V (Completed)	+4 Habitable Segments	None	10 years	10000
Dyson Sphere	Site	None	−5	5 years	1000 5000	Can only be constructed around regular single stars Cannot be built if there are habitable planets or anomalies present Upon completion, all rocky planets and moons in the system turn into frozen or cold barren worlds If the star has a mining station, it is removed when the megastructure is completed If any planet has the Terraforming Candidate modifier, it is removed The final stage can only be unlocked as part of the The Kaleidoscope situation A ruined Dyson Sphere is repaired to stage 5, and can be upgraded to stage 6 as with the constructed version
	Stage I (Frame)	None	None	10 years	5000 10000
	Stage II (Partial 25%)	+1000 Energy	None	10 years	5000 10000
	Stage III (Partial 50%)	+2000 Energy	None	10 years	5000 10000
	Stage IV (Partial 75%)	+3000 Energy	None	10 years	5000 10000
	Stage V (Completed)	+4000 Energy	None	10 years	5000 10000
	Stage VI (Wonder Sphere)	+600 Unity +30% Amenities	−30	1 year	3000 2500
Matter Decompressor	Site	None	−5	5 years	2500 5000	Can only be constructed around black holes Cannot be built if there are habitable planets or anomalies present If the black hole has a research station, it is removed when the megastructure is completed
	Stage I (Anchor)	+500 Minerals	−25	10 years	5000 12500
	Stage II (Lensing)	+1000 Minerals	−50	10 years	5000 12500
	Stage III (Boring)	+1500 Minerals	−75	10 years	5000 12500
	Stage IV (Completed)	+2000 Minerals	−100	10 years	5000 12500
Dyson Swarm	Array	Star Output +500%	−5	3 years	1000 500	Can only be constructed around standard stars (not black holes, neutron stars or pulsars)
	Constellation	Star Output +1500%	−10	3 years	2500 1000
	Stage III	Star Output +3000%	−20

Conquerable Ringworlds[]

Up to 8 ringworlds can spawn naturally in a game in various states. Damaged segments can be repaired with the Mega-Engineering technology for the same cost as finishing a new segment.

1 in the Sanctuary system. All 4 habitable sections are intact and each contains one pre-FTL civilization, none advanced beyond Steam Age. The system was abandoned by an Enigmatic Observer Fallen Empire but contains automated defense platforms totaling over 50k fleet power.
1 in the Cybrex Alpha system. It requires completing the Cybrex precursor event chain. The ringworld is completely ruined and requires repairs on each section.
1 in the Cybrex Beta system. It is only revealed if the Contingency sterilizes 20% of the galaxy. A short time after the Contingency is defeated, the Cybrex leave the galaxy, leaving the ringworld free for the taking.
1 in a random empty system if the Utopia DLC is enabled. It is completely ruined and each section requires repairing. If the Distant Stars DLC is enabled as well, the system has a 50% chance to contain a unique anomaly.
3 in the systems of the Ancient Caretakers if the Synthetic Dawn DLC is enabled. The ringworld in the home system has 3 intact and one ruined section, while the other two ringworlds are completely ruined and require each section to be repaired separately. If the Contingency appears and the Ancient Caretakers awaken to defend the galaxy, they also disappear like the Cybrex once the Contingency is defeated, leaving their systems free for the taking.
Each empire with the Shattered Ring origin starts in a ringworld system with 1-3 segments depending on the Guaranteed Habitable Worlds game rule. By default, only one empire with the origin can be generated, but force-spawning ignores that limit.

Ruined megastructures[]

Ruined dyson sphere — Ruined Dyson Sphere

Ruined versions of a multi-stage megastructure can be found while exploring the galaxy, with larger galaxies having a chance to spawn more ruined megastructures. Repairing them only requires the Mega-Engineering technology. If not yet researched, owning a system with a ruined megastructure also grants a ×20 weight for Mega-Engineering to appear.

While they upgrade from their broken to a fully functional state in one step, they do not count for any achievements. However, they do not count against any build limit for that particular megastructure either.

Ruined Megastructure	Time	Alloys	System notes
Dyson Sphere	7200	20000
Science Nexus	4800	15000
Sentry Array	4800	15000	Contains a Tomb World
Interstellar Assembly	3600	15000	Contains deposits on most celestial bodies
Matter Decompressor	4800	20000
Mega Art Installation	4800	20000	Is always a trinary system
Strategic Coordination Center	4800	15000
Mega Shipyard	3600	10000
Quantum Catapult	3600	10000	Is always a pulsar system
Quantum Catapult (Slingshot to the Stars)	3600	2500	Is always a pulsar system next to the origin homeworld

Empires with the Slingshot to the Stars origin can repair the special Quantum Catapult without the Mega-Engineering technology.

Aetherophasic Engine[]

The Aetherophasic Engine is a megastructure that appears in the capital system of every empire that reaches the final crisis level. Each stage of the megastructure requires gargantuan amounts of dark matter as well as 10 years to upgrade. If the system is conquered by another empire, the megastructure is ruined and can be repaired if the original empire reclaims it. Empires that reached the final crisis level and lost their Aetherophasic Engine but conquer another one have the option to take control of the new megastructure.

Visually, it resembles the Dyson Sphere generating unique system-wide visual effects the more it is upgraded.

Stage	Produces	Opinion	Dark matter required	Reward for destroyer	Effects
I	+100 Energy +250 Minerals +100 Naval capacity	0	0	200 Influence 5000 Alloys If crisis level 5, instead 10000 Dark matter	None
II	+200 Energy +500 Minerals +150 Naval capacity	0	20000	300 Influence 7500 Alloys If crisis level 5, instead 15000 Dark matter	Entering the Shroud displays a new set of messages
III	+400 Energy +1000 Minerals +200 Naval capacity	−1000	30000	400 Influence 10000 Alloys If crisis level 5, instead 20000 Dark matter	Within 1-2 years, 5% of the owned systems will be invaded by shroud avatars
IV	+800 Energy +2000 Minerals +250 Naval capacity	−1000	40000	600 Influence 15000 Alloys If crisis level 5, instead 30000 Dark matter	Within 1-2 years, 10% of owned systems are invaded by shroud avatars Up to 6 pops with the psionic trait die Up to 2 leaders with the psychic trait die
V	—	—	50000	—	Game victory The galaxy is destroyed

References[]

↑ Setting abandoned gateways to 0 blocks the use of gateway technology as an empire must discover at least one gateway to unlock the research. The Galactic Doorstep origin still spawns a pair of abandoned gateways if the setting is otherwise 0. Awakened Empires always build Gateways regardless of settings.

Game concepts

Exploration