
Mammalian Citadel
A starbase is the primary space station used throughout the game and is used for determining the ownership of a star system; construction, repair and maintenance of ships; collection and transportation of Trade Value; as well as acting as a strategic fortress during warfare.
Mechanics[]
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Please help with verifying or updating this section. It was last verified for version 3.10. |
Constructing a starbase requires first fully surveying the desired system. The build cost is 100 alloys and an additional
influence cost on top of that. The influence cost is a base of 75, multiplied by the number of hyperlane jumps, including bypasses, between the target systems and the empire's closest owned system. This is reduced by the
Slingshot to the Stars origin, which reduces the distance multiplier by 75%. For example, an adjacent system (1 jump) costs 75 influence, a system 2 jumps away costs 150 influence, or 94 influence with Slingshot to the Stars. Other modifiers to the total influence cost can be found below.
Once built, the starbase will appear orbiting the center point of the system. It cannot be destroyed by any regular means, but it can be dismantled by its owner during peacetime if it is of no more than outpost level (higher-level starbases will need to be downgraded first) and the system is not colonized. If a starbase is dismantled, the system reverts to being neutral and unowned and can then be claimed by any empire. Crisis factions, including the Khan and Gray Tempest, destroy starbases when they reduce it to 0 hull, though it is rebuilt as an outpost if their fleet leaves and a colonized world remains in the system. Star-Eaters also destroy the starbase when they crack the star.
Besides the initial influence cost, upgrading the starbase to a higher level costs only alloys. Aside from making the starbase more powerful due to better base stats and the addition of more weapon components, the upgrade also allows the owner to fit the starbase with different buildings and modules to increase its defensive capabilities and improve its contribution to the empire beyond its basic role of system control and defense. One such important module is the Shipyard which enables the construction of ships at the starbase. Having multiple shipyards on a starbase allows it to effectively act as a "fleet manufactory" by constructing several ships simultaneously in parallel. Shipyard build order is independent from the main build order of starbase.
Though it is not possible to design a starbase, its components will be auto-fitted with the latest advanced technology as soon as they are made available (at no additional cost to the owner).
Starbase capacity[]
The number of upgraded starbases an empire can support without penalty is determined by the starbase capacity. Every upgraded starbase exceeding that capacity adds
25% upkeep for all starbases. This modifier also affects the upkeep of modules and buildings on starbases. Regardless of their level, each starbase above outpost level occupies only one capacity slot and if the need arises, an empire can always downgrade existing starbases back to outpost level to reduce the number of upgraded starbases to within the cap.
The base starbase capacity is 3. This is increased by 1 for every 10 owned systems and can also be increased by the following:
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Please help with verifying or updating this section. It was last verified for version 3.9. |
Source | Starbase capacity |
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+6 |
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+5 |
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+4 |
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+4 |
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+2 |
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+2 |
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+2 |
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+2 |
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+2 |
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+2 |
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+1 |
Warfare behavior[]
Systems with starbases above outpost level require a higher influence cost to claim ( 25 influence). Additionally, those starbases grant a higher war-score if occupied successfully (10 occupation value). An additional benefit of upgraded starbases comes from their including an FTL inhibitor which prevents enemy ships from leaving the system via any hyperlane other than the one they arrived through until the starbase is disabled or occupied. This allows an FTL inhibitor-equipped starbase to turn strategically important systems into efficient choke points, preventing hostile fleets from bypassing the system without engaging the starbase and thereby forcing them into an engagement which may last long enough for reinforcements to arrive.
During war, an attacker must disable the enemy's starbase within the system in order to be able to seize control of any planets within said system. As starbases cannot be destroyed, this is achieved by reducing the Hull points down to 0, disabling the starbase. The starbase will then remain incapacitated for a duration of
30 days (after the latest attack), during which time any military ships in close proximity to the starbase will be able to gain control over it. If control of the starbase is uncontested, it will enter a self-repair phase and then become operational again as soon as it regains
5% Hull points. When a starbase is disabled, control of the starbase will be assigned to its owner, the war participant with the strongest system claim, or the war participant with the nearest fleet, in that order.
Occupied starbases are fully operational and can repair ships of the side that controls it, inhibit FTL for "enemy" ships, and manage defense platforms, all empire-wide bonuses will also be applied, including home territory modifiers (The Eternal Vigilance ascension perk's platform cap of the original owner is also temporarily retained). However, the buildings and modules cannot be changed, and the starbase cannot be upgraded or downgraded, although it can be returned to the owner.
It is worth noting that auto-upgrading a starbase can "gift" higher tech components to occupied starbases (including FTL inhibitors), while keeping their own more advanced components. They will stay equipped even if said starbase is reclaimed back, so repeated re-conquering might become harder for both sides.
Level[]
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Please help with verifying or updating this section. It was last verified for version 3.10. |
A starbase is auto-fitted with the latest components as soon as they are available to the empire. This is done automatically and has no additional cost for the empire - as such this also does not affect a starbase's level upgrade cost.
The weapon slots are fitted with the most effective kinetic and energy weapons (though not necessarily by equal division). The utility slots are divided equally between shield and
armor components (auto-fitting does not add hull components here), while the
auxiliary slot uses standard auto-fitting of a shield capacitor or auxiliary fire-control (whatever is available in order of priority).
Upgrading a starbase requires the technology of the same name and can only be done in sequential order - meaning that upgrading a basic outpost to a citadel requires going through every level in between to get to the desired level. Downgrading a starbase, however, reduces it to outpost level immediately, which removes all buildings and modules and any defense platforms over the outpost's capacity limit. Any resources invested into the starbase prior to downgrading will not be refunded.
Starting from starport level, all starbases have an FTL inhibitor if the
FTL Inhibition technology has been researched.
Note: The table lists the base properties of each starbase level. The actual values themselves will differ due to one's progress in-game (technology, tradition, and etc.), existing modifiers (if any) as well as individual starbase composition (buildings, modules, and etc.).
Level | ![]() |
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Modules | Buildings | ![]() |
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Weapons | Utilities | ![]() |
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100 | 100 | 1 | 0 | 0 | 3 | 0 | 5000 | 1000 | ![]() |
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200 | 360 | 2 | 2 | 1 | 6 | 8 | 10000 | 2000 | ![]() |
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500 | 720 | 3 | 4 | 2 | 9 | 16 | 20000 | 5000 | ![]() |
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1250 | 1080 | 4 | 6 | 3 | 12 | 24 | 40000 | 10000 | ![]() |
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3500 | 1440 | 5 | 6 | 4 | 15 | 32 | 80000 | 20000 | ![]() |
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Modules[]
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Please help with verifying or updating this section. It was last verified for version 3.10. |
A fully upgraded starbase can support up to 6 modules. It is possible to construct multiple modules of the same type and the starbase will be described in the outliner depending on the majority module type. Each module takes 180 days to construct and has an Energy upkeep of 1.
Module | Cost | Effects | Requirements | Description | |
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Shipyard | ![]() |
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A Shipyard may build one ship at a time, in parallel with other Shipyards. | |
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Anchorage | ![]() |
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Fleet anchorages are necessary to support the growth of our navy. | |
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Gun Battery | ![]() |
Adds two medium-size weapon slots to the Starbase. | ||
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Missile Battery | ![]() |
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Adds two torpedo weapon slots to the Starbase. | |
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Hangar Bay | ![]() |
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Adds a hangar for strike craft to the Starbase. | |
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Trade Hub | ![]() |
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A civilian docking area where merchants and traders can conduct business. |
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Solar Panel Network | ![]() |
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Advances in solar panel technology could offset the operating costs of our starbases. | |
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Detection Array | ![]() |
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Adds high-powered suite of external sensors, capable of detecting cloaked fleets. |
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Ancient Rampart |
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Defense platforms are a cost effective way to ensure our safety, but they need to be monitored from an operation center. Fortifying our Starbase to ensure its survivability in the event of an attack, and maximizing our capacity to network independent orbital defenses would give us more time to dispatch reinforcements. |
Buildings[]
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Please help with verifying or updating this section. It was last verified for version 3.10. |
A fully upgraded starbase can support up to 4 buildings. Unlike modules, it is only possible to construct a single building of any type. Building cost is reduced by −25% by the Modular Engineering technology. Many starbase buildings can also be built on Orbital Rings.
Building | Cost | Time | Upkeep | Effects | Orbital Ring | Requirements | |
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Resource Silo | ![]() |
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Target Uplink Computer | ![]() |
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Communications Jammer | ![]() |
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Max 1 per system | |
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Disruption Field Generator | ![]() |
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Max 1 per system |
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Crew Quarters | ![]() |
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Crew Gestation Chambers | ![]() |
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Service Umbilicals | ![]() |
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Fleet Academy | ![]() |
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Battle Simulators | ![]() |
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Black Hole Observatory | ![]() |
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Command Center | ![]() |
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Deep Space Black Site | ![]() |
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Defense-Grid Supercomputer | ![]() |
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Hydroponics Bay | ![]() |
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Hyperlane Registrar | ![]() |
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Listening Post | ![]() |
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Naval Logistics Office | ![]() |
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Nebula Refinery | ![]() |
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Offworld Trading Company | ![]() |
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Transit Hub | ![]() |
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Mining Bay | ![]() |
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Titan Assembly Yards | ![]() |
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Colossal Assembly Yards | ![]() |
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Ancient Shield Overcharger | ![]() ![]() |
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Interstellar Recruitment Office | ![]() |
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Dark Matter Resonance Chamber | ![]() ![]() |
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Starseed Garden | ![]() |
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Offspring Outlook | ![]() |
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Reloading Bay | ![]() |
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Cordyceptic Reanimation Facility | ![]() |
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Dimensional Shrine | ![]() |
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Ice Mining Station | ![]() |
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Dragon Hatchery | ![]() |
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Dark Matter Listening Post | ![]() ![]() |
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Enclave buildings[]
The following starbase buildings require an agreement with an enclave and/or the enclave's presence in the system. They cannot be constructed on Orbital Rings. Enclave buildings gain a bonus if the Unchained Knowledge resolution 3 is passed.
Building | Cost | Time | Upkeep | Effects | ![]() |
Requirements | Description | |
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Curator Think Tank | ![]() |
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By constructing a research facility entirely focused on learning from, and cooperating with, the Curators, we are able to make significant contributions to our scientific progress. | |
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Art College | ![]() |
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This zero-g Art College, operated in conjunction with the nearby Artisan Enclave, celebrates the beauty of outer space in the works produced by its talented students. | |
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Trader Proxy Office | ![]() |
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The Trader Enclaves enjoy special privileges on the Galactic Market, which can also benefit us. | |
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Salvage Works | ![]() |
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This bustling annex equips our engineering teams with a cornucopia of tools and spare parts, facilitating closer collaboration with the nearby Salvager Enclave. | ||
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Mercenary Garrison | ![]() |
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A collection of barracks hosting military contractors. These grizzled veterans organize regular drills for the rest of the crew, and stand ready to defend the station - as long as we pay them. |
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Shroud Beacon | ![]() ![]() |
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A psionic Beacon used to spawn a Shroud Tunnel in system. While the Shroud Beacon may be dismantled (or destroyed), the Tunnel itself cannot be removed. |
Precursor buildings[]
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Available only with the Ancient Relics DLC enabled. |
The following starbase buildings can only be constructed after completing the special project to delve into the secrets of one of the precursors and researching a unique technology. They cannot be constructed on Orbital Rings. Precursor buildings gain a bonus with the Archaeo-Engineers ascension perk.
Building | Cost | Time | Upkeep | Effects | ![]() |
Required technology | Description | |
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Cybrex Mining Hub | ![]() ![]() |
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To build their ring world, the Cybrex relied on highly efficient mining drones to survey and harvest orbital resources. Cybrex-made memory chips and sensors could outfit our own mining drones, so that we might put their millennia old algorithms to good use. |
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Irassian Naval Yards | ![]() ![]() |
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The Irassian astronaval tradition was unmatched in their time. Their shipyards produced a constant stream of ships for their navy and merchant fleets, which would ultimately be their downfall. With so many ships, and such a high reliance on them, the Irassians were powerless to quarantine the disease that would claim their empire. | |
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Yuht Astronomical Interferometer | ![]() ![]() |
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The Yuht were a paradoxical society, obsessed with the idea of finding other sentient species, yet refusing to accept that they were not alone. They were so focused on disproving any claim of alien life, that their bias found a way into their technology. However, with the proper modifications and calibrations, we could certainly fix their powerful detection arrays. | ||
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Zroni Storm Caster | ![]() ![]() ![]() |
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Zro is a fascinating element, prone to chaotic bursts of energy. We believe that with the right artifacts, we could use it to fuel spatial storms over entire solar systems. |
Defenses[]

Mammalian Ion Cannon
Because starbases are vital targets during warfare, an empire must ensure that they can maintain control over their own starbases to prevent their opponents from seizing control of the system. Investing resources into arming a starbase can allow it to function as a strong deterrent to enemy invasions, a powerful supporting power during a fleet battle in the system, and a starbase that is heavily armed enough can potentially even repel an entire enemy fleet by itself. Successfully maintaining control over every single starbase in the empire is by itself enough to allow an empire to end the war through a status-quo without losing any systems, earning them a defensive victory.
Basic starbase defense are turrets. Starbase turrets are always of medium size. Number of slots increase after each Starbase level upgrade and more can be added by building
Gun Batteries. Type of weapon cannot be chosen-slots will be filled by highest possible tier of automatically chosen type of weapon. Only possibility of diversification of turrets is to add
guided weapon by building
Missile Batteries or
aircrafts weapon by building
Hangar Bays. It is advised to reinforce critical starbases with defense platforms and to not rely only on turrets.
Defense platforms are smaller military stations that are deployed around the starbase and act as additional weapons platforms. They will engage any incoming hostile ships, effectively acting as a supporting weapon, by attacking and distracting them from focusing their efforts on the starbase itself, allowing the starbase to engage the enemies and support the defense platforms.
Unlike starbase auto-fitted turret design, they have two sections for weapon slots which can be outfitted with a wide variety of weapon configurations in Ship Designer, allowing for several designs to be built based on the different needs on each front and to be upgraded based on these designs. However, unlike ships, their designs cannot be switched once built, necessitating dismantling and completely rebuilding in order to change designs. It also renders any transferred platforms non-upgradeable.
When compared with ships, platforms are situated between Destroyer and Cruiser classes, their hull and armament slightly better than the former, while their armor-potential is equivalent to the latter. However, due to them having no evasion whatsoever, individual platforms are still very vulnerable, and if a strong, sustainable firepower is a priority, it is wiser to put more turrets on the base itself and only add in defense platforms once the starbases available armaments have been maxed out.
Basic capacity of defense platforms is 3. The defense platform capacity for starbases can be increased by the following:
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Please help with verifying or updating this section. It was last verified for version 3.9. |
Source | Defense platform cap (empire) |
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+12 |
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+8 |
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+8 |
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+5 |
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+5 |
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+4 |
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+4 |
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+2 |
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+2 |
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+1 |
Ion Cannon[]
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Available only with the Apocalypse DLC enabled. |
In addition to the regular defense platforms, a citadel-level starbase is also capable of hosting an Ion Cannon, a more powerful platform type that carries a weapon identical to the Perdition Beam titan weapon. It is titan-class hull-wise, but only battleship-class armor-wise. Each Ion Cannon has an upkeep of 8 energy.
An ion cannon platform is equivalent to 8 defense platforms in terms of capacity slots and can only be constructed on citadel-level starbases.
Defense platform modifiers[]
Defense platforms have +30% Weapons Range. Additional modifiers which affect various defense platform parameters are summarized below. Note that general modifiers to ship hull, armor, shield, and damage also apply to defense platforms.
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Damage |
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+100% | ![]() |
+75% | ![]() |
+50% | ![]() |
+50% | ![]() |
+33% | ![]() |
+25% | ![]() |
+25% | ![]() |
+10% | ![]() |
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Hull points |
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+100% | ![]() |
+75% | ![]() |
+50% | ![]() |
+50% | ![]() |
+33% | ![]() |
+25% | ![]() |
+10% | ![]() |
+500 | ![]() |
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Build cost |
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−75% | ![]() |
−50% | ![]() |
−33% | ![]() |
−25% | ![]() |
−25% | ![]() |
−15% | ![]() |
+25% | ![]() |
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Build speed |
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+100% | ![]() |
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Upkeep |
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−75% | ![]() |
−50% | ![]() |
−25% | ![]() |
−25% | ![]() |
+25% | ![]() |
References[]
Exploration | Exploration • FTL • Anomaly • Archaeological site • Relics • Pre-FTL species • Fallen empire • Events • Spaceborne aliens • Enclaves • Guardians • Marauders • Caravaneers |
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Diplomacy | Diplomacy • Relations • Galactic community • Federations • Subject empires • Intelligence • AI personalities |
Warfare | Warfare • Space warfare • Land warfare • Starbase • Ship • Ship designer • Crisis |
Others | The Shroud • L-Cluster • Unique systems • Preset empires • AI players • Easter eggs |