About the Game
A starship builder perfect for fans of games like FTL, Starsector, SPAZ, Space Engineers, Escape Velocity, Avorion, and more.
Design awesome starships using intuitive ship creation tools that are easy to learn but hard to master. Fully customize your ship's shape and floor plan, choosing where to place individual modules including weapons, engines, hallways, and crew's quarters. Your ship's design is key to its survival, and every decision you make will impact its performance in battle. Easily share your designs with others through the Steam Workshop, Forums, and Discord.
A ship's crew is its lifeblood. Numbering from half-a-dozen to a thousand or more individually-simulated people, your crew will pilot your ships, operate their weapons, and carry munitions. How efficiently they operate determines how well your ships will perform in combat. Your crew are autonomous but you can optionally customize their behavior with specific roles and job priorities.
Command your ship or fleet in real-time tactical battles. Combat is physics-driven, explosive, and immensely satisfying. Each module can be individually targeted and destroyed, and whole ships can even break apart into multiple pieces. Target an enemy's weapons to eliminate its offensive capability, destroy its shields to lower its defenses, or go for the kill by taking out its reactor.
Become the most famous "Cosmoteer'' in the universe by battling A.I. ships, taking on contracts for factions, earning loot, and upgrading your own ship while exploring a procedurally-generated galaxy, alone or in online co-op with friends. Then test your ships design and command skills online against other players in multiple PvP battle modes. Or let your imagination fly free in the Creative Mode where you can build whatever you want with unlimited resources.
Still want more? A powerful modding framework and Steam Workshop will keep Cosmoteer constantly feeling fresh with new player-created weapons, modules, and other enhancements.
Cosmoteer has a friendly and growing community on Discord. Join 20k+ fellow Cosmoteers today!
Design awesome starships using intuitive ship creation tools that are easy to learn but hard to master. Fully customize your ship's shape and floor plan, choosing where to place individual modules including weapons, engines, hallways, and crew's quarters. Your ship's design is key to its survival, and every decision you make will impact its performance in battle. Easily share your designs with others through the Steam Workshop, Forums, and Discord.
A ship's crew is its lifeblood. Numbering from half-a-dozen to a thousand or more individually-simulated people, your crew will pilot your ships, operate their weapons, and carry munitions. How efficiently they operate determines how well your ships will perform in combat. Your crew are autonomous but you can optionally customize their behavior with specific roles and job priorities.
Command your ship or fleet in real-time tactical battles. Combat is physics-driven, explosive, and immensely satisfying. Each module can be individually targeted and destroyed, and whole ships can even break apart into multiple pieces. Target an enemy's weapons to eliminate its offensive capability, destroy its shields to lower its defenses, or go for the kill by taking out its reactor.
Become the most famous "Cosmoteer'' in the universe by battling A.I. ships, taking on contracts for factions, earning loot, and upgrading your own ship while exploring a procedurally-generated galaxy, alone or in online co-op with friends. Then test your ships design and command skills online against other players in multiple PvP battle modes. Or let your imagination fly free in the Creative Mode where you can build whatever you want with unlimited resources.
Still want more? A powerful modding framework and Steam Workshop will keep Cosmoteer constantly feeling fresh with new player-created weapons, modules, and other enhancements.
Cosmoteer has a friendly and growing community on Discord. Join 20k+ fellow Cosmoteers today!
Screenshots
11 images
Version Information
Steam Patch Notes
Official update history
On the site: Build 23161854
Up to date
Release Candidate 0.30.5 - Custom Weapon Ranges & Arcs, Balance Changes, New Ships, & Bug Fixes
Cosmoteer release candidate 0.30.5 is now available for testing! (To play this release candidate, you must opt in to test it. Please see this post for info on how to test release candidates.)
This release candidate adds the ability to customize the range, firing arc, and direction of your weapons, adds new ships, makes various quality-of-life improvements, (hopefully) improves balance, and fixes bugs. It also likely solves most of the freezing issues that many players on Linux have been experiencing. (Thanks to all of you who sent in bug reports and logs and helped test the fix!)
Thanks for testing!
RC1 Patch Notes:
- New Feature: Custom Weapon Ranges, Arcs, & Directions:
- Added a new "Set Range/Arc/Direction" tool that lets you customize the maximum range and firing arc of your weapons, or aim them in a fixed direction. Select one or more weapons, press the button (or Alt+R by default), and then drag the displayed edges.
- The tool can be used both during normal gameplay and in build mode (where it also supports mirror mode).
- While the tool is enabled, hold keys for additional modes: Shift for "Edit All" (adjust all selected weapons at once), Ctrl for "Precision" (snap to 0.1 increments instead of 1.0), Alt for "Rotation" (rotate the arc without changing its size), Tilde (~) for "Symmetry" (adjust both edges of the arc at once), and Alt + Tilde to aim a weapon in a fixed direction.
- Right-click on an individual edge to reset all highlighted edges. Right-click on the "Set Range/Arc/Direction" button to reset all selected weapons.
- This replaces the old "Aim" button used by Ion Prisms and Chainguns and is now available for all weapons. (To target a Prism on another Prism, use the regular "Target" button.)
- The Micromanagement and Ion Prisms tutorials have been updated to explain this new tool.
- Added a new "Set Range/Arc/Direction" tool that lets you customize the maximum range and firing arc of your weapons, or aim them in a fixed direction. Select one or more weapons, press the button (or Alt+R by default), and then drag the displayed edges.
- Balance:
- Structure:
- Most bullets and beams now penetrate through structure, retaining 60% of their damage for each structure tile they pass through (down to a minimum of 3%).
- Most bullets and beams now penetrate through structure, retaining 60% of their damage for each structure tile they pass through (down to a minimum of 3%).
- Ship Physics:
- Reverted ship drag to its pre-Meltdown Update values.
- Reverted ship drag to its pre-Meltdown Update values.
- Projectiles:
- Reduced most projectile speeds by 1/6, effectively reverting to pre-Meltdown Update speeds.
- Mine and overclocked Large Cannon shrapnel can now be targeted and shot down by Point Defenses and Flak.
- Hitscan weapons such as Flak and Ion Beams should now find targets more quickly.
- Reduced most projectile speeds by 1/6, effectively reverting to pre-Meltdown Update speeds.
- Heat Mechanics:
- Heat diffusion now requires a contiguous path between parts.
- Heat diffusion now requires a contiguous path between parts.
- Fire:
- Fires started by explosions (reactors, factories, missile/mine storage, Ion Prisms, etc.) now start at full strength (1.3%->100%; this was a bug)
- Fires started by explosions (reactors, factories, missile/mine storage, Ion Prisms, etc.) now start at full strength (1.3%->100%; this was a bug)
- Armor (all):
- Removed hidden -25% heat damage resistance.
- Removed hidden -25% heat damage resistance.
- Small Thruster (Overclocked):
- Increased power usage (0.03->0.09)
- Increased power generation (0.015->0.0225)
- No longer generates power while actively thrusting.
- Reduced heat generation at 100% thrust (250/s->200/s)
- Now generates heat while generating power (125/s)
- Reduced the default "Supply Battery" job priority to 1 since Small Thrusters generate their own power.
- Increased power usage (0.03->0.09)
- Boost Thruster (Overclocked):
- Increased heat generation while boosting by 50% (this was already intended but was bugged until now)
- Very, very, very slightly reduced heat generation while not boosting (676/s->675/s; this was also a bug)
- Increased heat generation while boosting by 50% (this was already intended but was bugged until now)
- Ion Beam Emitter (Overclocked):
- Reduced damage vs parts (180->150)
- Reduced damage vs shields (180->120)
- Reduced damage at max range (100%->80%)
- Reduced damage vs parts (180->150)
- Standard Cannon (Overclocked):
- No longer has a range and projectile speed advantage compared to non-overclocked.
- No longer has a range and projectile speed advantage compared to non-overclocked.
- Chaingun:
- Protective shells now have 70% thermal damage resistance when closed.
- Reduced damage vs structure (600->150)
- Reduced impulse vs structure (10->5)
- Protective shells now have 70% thermal damage resistance when closed.
- Mining Laser (Overclocked):
- Area damage no longer ignores shields.
- Area damage no longer ignores shields.
- Thermal Resonance Lance:
- Heat application now requires a contiguous path between parts.
- Heat application now requires a contiguous path between parts.
- Thermal Canister Missile:
- Reduced applied heat per missile (8500->5000). Capacity is unaffected.
- Reduced applied heat per missile (8500->5000). Capacity is unaffected.
- Structure:
- Built-In Ships:
- Added 16 new Monolith combat ships: Algorithm, Blockchain, Fortbreaker, Hangman, Inquisitor, Kalashnikov, Marshal, Meteor, Project Eilifnir, Project Laevateinn, Project Svalinn, Septadent, Stake Driver, Tercio, Tribunal, Trishula
- Added 2 new Monolith stations: Large Monolith Arms Depot II, Large Monolith Arms Depot III
- Added 2 new Monolith defense platforms: Large HE Missile Platform, Large Deck Cannon Platform
- Added 2 new Cabal combat ships: Flegetonte Minor, Ignis Vorax
- Added 2 new Cabal stations: Med Cabal Arms Depot II, Large Cabal Arms Depot II
- Added 2 new Cabal defense platforms: Large Ion Platform, Large HE Missile Platform
- Added 5 new Imperium combat ships: Aegolius, Athene, Aves, Esarhaddon, Viduidae
- Added 1 new Imperium defense platform: Large Ion Platform
- Added 9 new Fringe combat ships: Aragh Sagi, Oghi, Orujo, Quicksilver Skirmisher, Rakija, Shrapnel Kedge, Smokestack, Yesterday's Lie, Zivania
- Added 5 new Fringe trade ships: Affordable, Barrel's Bottom, Better Than Nothing, Drossbarge, Melquiades
- Added 2 new Fringe stations: Med Fringe Trade Station II, Large Fringe Trade Station II
- Added 2 new Fringe defense platforms: Large HE Missile Platform, Large Deck Cannon Platform
- Added 10 new House Io combat ships: Adrammelech, Andrus, Behemoth, Belphegor, Glasya, Haborym, Labolas, Leviathan, Mammon, Melchom
- Added 2 new House Io defense platforms: Large TRL Platform, Large HE Missile Platform
- Added the winning ships from the January 2026 ship design contest.
- Miscellaneous updates to existing built-in ships.
- Added 16 new Monolith combat ships: Algorithm, Blockchain, Fortbreaker, Hangman, Inquisitor, Kalashnikov, Marshal, Meteor, Project Eilifnir, Project Laevateinn, Project Svalinn, Septadent, Stake Driver, Tercio, Tribunal, Trishula
- Career:
- Abandoned civilian trade and transport ships may now sometimes be found.
- It is no longer possible to go into debt in Ironman Mode.
- Abandoned civilian trade and transport ships may now sometimes be found.
- Multiplayer:
- The PvP "ring of death" now kills crew.
- The PvP "ring of death" now kills crew.
- Ship Painting:
- Added 7 new decals: 'fade_straight_triangle_half_empty_2', 'fade_stripe_slant_full', 'fade_triangle_eighth_full', 'fade_triangle_half_full', 'fade_triangle_quarter_full', 'fade_triangle_wedge_full', and 'fade_triangle_wedge_full_corner'.
- The 'shape_poly_7' decal is now properly centered.
- Tweaked the 'shape_corner_square_1' and 'shape_corner_square_arrow' decals so that they don't intrude slightly past the diagonal halfway line.
- Added 7 new decals: 'fade_straight_triangle_half_empty_2', 'fade_stripe_slant_full', 'fade_triangle_eighth_full', 'fade_triangle_half_full', 'fade_triangle_quarter_full', 'fade_triangle_wedge_full', and 'fade_triangle_wedge_full_corner'.
- User Interface:
- Pressing the "focus" key (F by default) twice will now zoom in on the selected ship, or zoom to fit all selected ships if multiple are selected.
- Individual resources can now be pinned so that your ship's quantity and capacity of that resource is always displayed in the top-right corner of the screen. To pin (or unpin) a resource, right-click it in the Resources toolbox.
- The nearby missions HUD can now be minimized using a new toggle. Right-click the toggle to set the number of missions displayed.
- Mining Lasers and Manipulator Beams now have an "Always Crew" toggle. When turned off, the part will only be crewed when it has a target.
- Added a hotkey (Ctrl+Shift+C by default) which resets the crew's positions in Creative Mode.
- Added a setting to require holding the "append selection" key (Shift by default) in order to drag favorite parts and decals.
- When buying blueprints, hovering over a part's icon now shows a tooltip with that part's stats.
- Hovering over a crew quarters while assigning crew now displays how many of its crew are assigned.
- Overclocked Ion Beam Emitters now have a "Lightning Interval" stat.
- The single-player "chat" toggle is now disabled when the message history is empty.
- Long resource names no longer overlap their icons.
- Clarified the tooltip for the "I Hate Exploration" toggle.
- Fixed the Small and Medium Reactor tooltips so that they don't incorrectly mention increased power capacity.
- The Japanese translation is now correctly named 日本語 ("Japanese") instead of 英語 ("English").
- Clarified the Simplified Chinese translation for "Laser Blaster" (激光炮->激光爆能炮).
- Pressing the "focus" key (F by default) twice will now zoom in on the selected ship, or zoom to fit all selected ships if multiple are selected.
- Performance:
- Game asset loading can now run on parallel CPU cores, improving load times. (This was already enabled in developer mode but is now enabled in non-developer mode as well.)
- Game asset loading can now run on parallel CPU cores, improving load times. (This was already enabled in developer mode but is now enabled in non-developer mode as well.)
- Compatibility:
- Removed 32-bit/x86 support. (Steam itself no longer supports 32-bit/x86, and Cosmoteer was actually already crashing on load due to out-of-memory errors, but now it's official.)
- Removed 32-bit/x86 support. (Steam itself no longer supports 32-bit/x86, and Cosmoteer was actually already crashing on load due to out-of-memory errors, but now it's official.)
- Bug Fixes:
- Possible fix for frequent multiplayer disconnects that some players have been experiencing.
- Possible fix for random freezes on Linux. (Preliminary testing indicates this solves freezes for most Linux players.)
- In rare circumstances, saved games could become corrupted causing a "Can't modify components while they are being saved" error when loading them. (These corrupted saves should now also load again.)
- Crash with error message "Tried to spend more resources than we had" in some situations when making ship changes with "I Hate Crew Construction" enabled.
- Crash with error message "Already doing an FTL jump" in some circumstances when jumping to a different star system.
- "Object reference not set to an instance of an object" error when loading games that were saved while the player is wanted and there are parts queued for deconstruction.
- Crash in some circumstances when using "load and replace" with overclocked or thermal parts.
- Crash when viewing the galaxy map with some rare galaxy seeds.
- The game would end when reconstructing a ship and losing vision due to fog of war.
- In some circumstances, crew wouldn't finish ship construction after loading a saved game where construction had already been started.
- With crew construction enabled, deliberately replacing a part with structure tiles would make those structure tiles un-repairable when damaged.
- With crew construction enabled, replacing an armor wedge with a structure wedge would cause the structure wedge to also be deconstructed, breaking construction.
- Crew would "dump" resource nuggets into outer space when canceling a trade or construction.
- Crew would sometimes get "stuck" at overclocked capacitors that had more than 0 but fewer than 3 stored batteries.
- Launchers added in blueprint mode could calculate the incorrect "Ship Design Value" for the Launcher and its munitions.
- Overclocked Deck Cannon penetration impulse wasn't reducing with its remaining damage pool.
- The TCM Launcher fired its right-hand missile from the center of the launcher instead of from the right.
- Large Shield arcs were not being blocked properly by megaroids.
- The fire icon effect would sometimes not be shown.
- The Battle Helper would ignore the presence of suns, often spawning ships inside of them.
- Possible fix for frequent multiplayer disconnects that some players have been experiencing.
- Modding:
- Bullets and beams can now be made to apply penetration damage/effects to additional structure tiles beyond just the first hit. This includes a new 'StructuralDamageRetentionPerHit' parameter (defaults to zero).
- Most rules loading errors will now show the relevant line and character numbers.
- Added a 'UseContiguity' bool to GridStatusApplication hit effects. ('Traversing' requires underlying parts to be connected.)
- Added 'UseContiguity' to status diffusion rules, requiring contiguity between two tiles for diffusion to occur.
- Fixed long load times when mods create long bullet reference trees.
- Fixed the AddBase mod action not being usable on [] lists inside {} groups.
- Fixed StatusRemap value modifiers ignoring the 'BaseStatusValue' rule.
- Fixed issues with 'Interpolated' status value type conversions:
- 'ExplosiveDamage' hit effects using interpolated values had a much lower chance than intended.
- 'StatusApplication' hit effects using interpolated values and one or more 'DivideValueBy*' rules for statuses with a non-zero minimum value would divide the raw value.
- 'StatusRemap' value modifiers using interpolated values and one or more 'IgnoreValues*Range' rules would compare against the raw value.
- Any 'Status*' value modifiers (excluding remap) using interpolated values and a non-zero 'BaseStatusValue' would interpret 'BaseStatusValue' as a raw value.
- 'ExplosiveDamage' hit effects using interpolated values had a much lower chance than intended.
- Fixed Tile/PartQuad effects with a fade-in time of 0 sometimes not being shown.
- Bullets and beams can now be made to apply penetration damage/effects to additional structure tiles beyond just the first hit. This includes a new 'StructuralDamageRetentionPerHit' parameter (defaults to zero).
RC2 Patch Notes:
- Custom Weapon Ranges, Arcs, & Directions:
- The "Set Range/Arc/Direction" tool can now also be used to set the direction that turreted weapons will rest at when they have no targets to shoot at. Drag the dotted arrow line to change it.
- The "Set Range/Arc/Direction" tool can now also be used to set the direction that turreted weapons will rest at when they have no targets to shoot at. Drag the dotted arrow line to change it.
- Balance:
- Weapons vs Structure:
- Reduced the damage that bullets and beams retain for each structure tile they pass through (60%->50%).
- Thermal Resonance Lances now use the same minimum penetration damage as other weapons (5%->3%).
- Reduced the damage that bullets and beams retain for each structure tile they pass through (60%->50%).
- Weapons vs Structure:
- Reduced Railgun damage vs structure (2500->1200).
- Railguns now use the same structure penetration values as other weapons (80%->50% retained per tile, 5%->3% minimum).
- Boost Thruster (Overclocked):
- Reduced boost thrust (24kN->14kN).
- Reasoning: Overclocked Boost Thrusters were already oppressive and were made even stronger by the drag reversion. This is a temporary fix until a more holistic solution is implemented.
- Reduced boost thrust (24kN->14kN).
- Capacitor (Overclocked):
- Now creates a large heat blast when destroyed (scaled by the number of stored batteries).
- Now creates a large heat blast when destroyed (scaled by the number of stored batteries).
- Nuke Launcher:
- Increased maximum firing arc (200°->360°). The default firing arc remains unchanged.
- Increased maximum firing arc (200°->360°). The default firing arc remains unchanged.
- Small Thruster (Overclocked):
- The RC1 changes now also apply to the 2-way and 3-way Small Thrusters. (This was an oversight in RC1.)
- The RC1 changes now also apply to the 2-way and 3-way Small Thrusters. (This was an oversight in RC1.)
- Armor (all):
- The removal of the hidden -25% heat damage resistance now also applies to armor wedges, triangles, 2x1 armor, and armor/structure hybrids. (This was an oversight in RC1.)
- The removal of the hidden -25% heat damage resistance now also applies to armor wedges, triangles, 2x1 armor, and armor/structure hybrids. (This was an oversight in RC1.)
- Ammo, Mine Parts, & Missile Parts:
- Now only explode when the part storing them becomes scorched, instead of having a random chance to explode whenever they take fire damage.
- Now only explode when the part storing them becomes scorched, instead of having a random chance to explode whenever they take fire damage.
- Resource Management:
- When a supplier (such as a factory) is supply-chain-assigned to a storage bay that has no tiles designated for its specific type of resource but has at least one undesignated tile, the supplier will no longer send resources to other destinations it's not assigned to.
- When a supplier (such as a factory) is supply-chain-assigned to a storage bay, nothing else not assigned to that storage bay will be able to send the same type of resource to it, regardless of whether its tiles are designated for that type of resource. (They were already unable to do so for any tiles designated for that type of resource.)
- When a supplier (such as a factory) is supply-chain-assigned to a storage bay that has no tiles designated for its specific type of resource but has at least one undesignated tile, the supplier will no longer send resources to other destinations it's not assigned to.
- Built-In Ships:
- Added 1 new Imperium defense platform: Large HE Missile Platform
- Miscellaneous fixes to RC1 ships.
- Added 1 new Imperium defense platform: Large HE Missile Platform
- User Interface:
- Translation updates for all languages except Simplified Chinese. (That should arrive in time for the stable 0.30.5 update.)
- Translation updates for all languages except Simplified Chinese. (That should arrive in time for the stable 0.30.5 update.)
- Bug Fixes:
- RC Bugfix: Weapon targeting was broken when given fixed- or very-narrow custom firing arcs.
- RC Bugfix: Multiplayer desync when auto-purchasing resources for construction and different players could afford different amounts of those resources.
- RC Bugfix: Thermal Resonance Lances were applying heat in a "cross" shape.
- RC Bugfix: The direction line for Ion Prisms that is shown when adjusting an attack command wasn't getting clipped by its own ship when the prism was given a fixed direction.
- Using the "Load Ship (Replace Existing)" feature and checking "Also Load Resource Assignments" would clear the existing resource and supply assignments without loading the new ones.
- Spawning or restocking ships with Processor Factories or Uranium Enrichers would cause them to immediately produce a processor or enriched uranium without consuming any ingredients.
- In Domination mode, under-construction parts could be "repaired" to completion for free inside the spawn circle. These parts could then be used at zero cost or sold for free money.
- In Domination mode, restocking resources inside the spawn circle would instantly transfer those resources to any under-construction parts whose construction had been queued when outside the spawn circle.
- RC Bugfix: Weapon targeting was broken when given fixed- or very-narrow custom firing arcs.
- Modding:
- Added an 'AllowVertexContiguity' rule to GridStatusApplication hit effects, which counts parts with touching corners as diagonally contiguous.
- Added a 'StatusResponse' rule to resource rules.
- Added an 'AllowVertexContiguity' rule to GridStatusApplication hit effects, which counts parts with touching corners as diagonally contiguous.
RC3 Patch Notes:
- Custom Weapon Ranges, Arcs, & Directions:
- Weapon ranges, arcs, and directions can no longer be edited during gameplay when the ship has no control.
- Weapon ranges, arcs, and directions can no longer be edited during gameplay when the ship has no control.
- Balance:
- Capacitor (Overclocked):
- Reduced power capacity (72->48).
- Reduced power capacity (72->48).
- Capacitor (Overclocked):
- Built-In Ships:
- Miscellaneous updates to existing built-in ships.
- Miscellaneous updates to existing built-in ships.
- User Interface:
- Keybinds for non-English keyboards should now more accurately display the actual symbol printed on the key.
- The key combo used to open the developer menu in developer mode can now be customized in the control settings.
- Translation updates for Simplified Chinese.
- The Spanish translation now uses a consistent translation of "parts" (piezas->partes).
- Keybinds for non-English keyboards should now more accurately display the actual symbol printed on the key.
- Graphics:
- Overclocked Capacitors now have an animation when overclocking is toggled, and their stored battery art has been updated to reflect the reduced capacity.
- Overclocked Capacitors now have an animation when overclocking is toggled, and their stored battery art has been updated to reflect the reduced capacity.
- Bug Fixes:
- RC Bugfix: Weapons given a fixed direction or a very narrow custom firing arc would sometimes miss their targets.
- RC Bugfix: Tractor Beams wouldn't shut off when their target moved outside of their custom firing arc.
- Possible fix for certain "Function does not accept floating point Not-a-Number values" crashes.
- The Chaingun's "no ammo" indicator was appearing later than it should have after running out of ammo.
- RC Bugfix: Weapons given a fixed direction or a very narrow custom firing arc would sometimes miss their targets.
RC4 Patch Notes:
- Built-In Ships:
- Most trade stations have been updated to always crew their Manipulator Beams, which should improve response times when transferring resources and assisting with construction.
- Most trade stations have been updated to always crew their Manipulator Beams, which should improve response times when transferring resources and assisting with construction.
- Bug Fixes:
- RC Bugfix: Crash when deleting ships.
- RC Bugfix: Nukes fired in direct control mode wouldn't home to their target if it was outside their firing arc.
- RC Bugfix: For weapons with firing arcs greater than 180 degrees, adjusting their resting direction could cause glitches when then changing the resting direction to the other side.
- RC Bugfix: Overclocked Flak would create multiple shrapnel clouds when its beam passed through structure.
- Bugfix: Turret weapons wouldn't auto-fire at structure tiles if the enemy ship had any non-structure tiles, even if there are only structure tiles within the weapon's firing range/arc.
- RC Bugfix: Crash when deleting ships.
RC5 Patch Notes:
- Custom Weapon Ranges, Arcs, & Directions:
- "Precision" mode (hold Ctrl) now snaps to 0.01 increments instead of 0.1.
- "Precision" mode (hold Ctrl) now snaps to 0.01 increments instead of 0.1.
- Balance:
- Small Laser Blaster (Overclocked):
- Reduced damage (350->200)
- Reduced power usage per shot proportionally (0.14->0.08)
- Reduced damage (350->200)
- Radiator:
- Reduced health (4000->3000)
- Reduced health (4000->3000)
- Explosive Charge:
- Can now be detonated even if the ship doesn't have control.
- Can now be detonated even if the ship doesn't have control.
- Ammo, Mine Parts, & Missile Parts:
- Explosions caused by stored resources becoming scorched are now much weaker, scaling by the number of full stacks instead of the number of individual resources (20x weaker for ammo, 8x for mine parts, 10x for missile parts; this was a bug).
- Parts that store these resources internally (such as cannons, Chainguns, missile launchers, and factories) now explode when destroyed or scorched, the same way storage bays already did. (This was also a bug.)
- Explosions caused by stored resources becoming scorched are now much weaker, scaling by the number of full stacks instead of the number of individual resources (20x weaker for ammo, 8x for mine parts, 10x for missile parts; this was a bug).
- Small Laser Blaster (Overclocked):
- Built-In Ships:
- Added 4 new House Io combat ships: Rahovart, Xapahn, Xarpa, Xebelius
- Added 1 new House Io station: Large Ionian Arms Depot III
- Miscellaneous updates to existing built-in ships.
- Added 4 new House Io combat ships: Rahovart, Xapahn, Xarpa, Xebelius
- User Interface:
- Double-pressing the "focus" key (F by default) to zoom in now requires the two presses to be in quick succession.
- Double-pressing the "focus" key (F by default) to zoom in now requires the two presses to be in quick succession.
- Bug Fixes:
- RC Bugfix: The tooltips for overclocked 2-way and 3-way Small Thrusters didn't reflect the RC1 changes.
- RC Bugfix: The tooltips for overclocked 2-way and 3-way Small Thrusters didn't reflect the RC1 changes.
- Modding:
- Added 'DoResourceDeathEffects' and 'DoResourceResponseEffects' rules to resource storage components (both default to true).
- Added 'DoResourceDeathEffects' and 'DoResourceResponseEffects' rules to resource storage components (both default to true).
RC6 Patch Notes:
- Custom Weapon Ranges, Arcs, & Directions:
- Holding Shift+Alt while adjusting the direction of multiple Headlights converges them all on the same point.
- Holding Shift+Alt while adjusting the direction of multiple Headlights converges them all on the same point.
- Balance:
- Reduced the starting strength of fires started by explosions from 100% to between 20%-40%.
- Reduced the starting strength of fires started by explosions from 100% to between 20%-40%.
- Built-In Ships:
- Miscellaneous updates to existing built-in ships.
- Miscellaneous updates to existing built-in ships.
- Ship Painting:
- Removed the RC1 decals 'fade_triangle_half_full' and 'fade_triangle_wedge_full' because they were inversions of existing decals. Ships using them will automatically be switched to the equivalent inverted 'fade_corner_straight' and 'fade_corner_wedge' decals.
- Removed the RC1 decals 'fade_triangle_half_full' and 'fade_triangle_wedge_full' because they were inversions of existing decals. Ships using them will automatically be switched to the equivalent inverted 'fade_corner_straight' and 'fade_corner_wedge' decals.
- User Interface:
- Thermal Amplification Pumps and Thermal Dilation Pumps now show a Recommended Crew value.
- Thermal Amplification Pumps and Thermal Dilation Pumps now show a Recommended Crew value.
- Bug Fixes:
- RC Bugfix: Flak would create multiple shrapnel clouds when hitting structure.
- RC Bugfix: Tractor Beams wouldn't target a ship whose center was outside their custom firing arc, even if other parts of that ship were inside it.
- RC Bugfix: The default attack distance didn't take into account weapons with narrow custom firing arcs.
- RC Bugfix: Thermal Resonance Lances weren't heating parts connected only diagonally.
- RC Bugfix: Ammo, mine, and missile factories/launchers showed their full "destroyed" visual effects when scorched instead of their "scorched" effects, and factories' scorch explosions weren't scaled by the resources stored in them.
- Kills caused by heat diffusing between parts weren't credited to the correct player.
- Thermal Resonance Lances applied heat in the wrong pattern on megaroids.
- Overclocked Ion Beams didn't correctly check for "splashing" when targeted at Ion Prisms on other friendly ships.
- Setting or clearing a key/button for a Direct Control Binding didn't immediately update whether the binding option is available in the part's hamburger menu.
- RC Bugfix: Flak would create multiple shrapnel clouds when hitting structure.
- Modding:
- In order to prevent malicious code injection, the Python code snippets in music and codex rules files are now limited to a very small subset of Python syntax.
- The 'StatusValue' of ExplosiveDamage hit effects can now be a random range.
- Fixed blueprint NetworkValueReceivers not correctly combining values from other subnets (directional routes).
- In order to prevent malicious code injection, the Python code snippets in music and codex rules files are now limited to a very small subset of Python syntax.
- Bugfix: When running in developer mode, mods that add new ship classes would crash the game during loading with a "cannot be used in the demo" error. (This bug was introduced in yesterday's 0.30.4b hotfix.)
- Possible fix for rare, random crashes during gameplay.
Attention Linux Players: We're aware that many of you are experiencing random and often frequent freezes/crashes since the 0.30.4 update. We're currently in communications with the Proton team about these, and they need your Proton log files in order to investigate the issue. Please see this FAQ about how to turn on and find the Proton log file. Please post the log file here or on Discord. (Warning: These files can be extremely large, so you may need to compress it or extract the final 10k lines or so.) In the meantime, some players have reported success by changing the version of Proton used, and if that doesn't work then rolling Cosmoteer back to 0.30.3 (available via the beta branches) should definitely resolve it.
- Bugfix: The game would sometimes load forever while jumping to a new star system.
- When updating an existing Steam Workshop item, the name, description, and preview image will no longer be updated unless you specially check a box to do so.
Cosmoteer release candidate 0.30.4 is now available for testing! (To play this release candidate, you must opt in to test it. Please see this post for info on how to test release candidates.)
This release candidate adds "Ironman Mode" to Career, adds new ships, improves balance, and fixes bugs.
Thanks for testing!
RC1 Patch Notes:
- Balance:
- Small Shield (Overclocked):
- 'Extended' health reduced (15000->12000)
- 'Reinforced' health increased (30000->39000)
- 'Extended' health reduced (15000->12000)
- Flak (Overclocked):
- Reduced shrapnel cloud health (800->400)
- Reduced shrapnel cloud lifetime (7s->4s)
- Reasoning: Overclocked Flak were too cost-effective at blocking damage.
- Reduced shrapnel cloud health (800->400)
- Ion Beam Emitter:
- Increased battery capacity (10->16)
- Reasoning: Overclocked Ion Beams were too difficult to sustain.
- Increased battery capacity (10->16)
- Thermal Resonance Lance:
- Reduced turret speed (60->30)
- Reasoning: Resonance Lance was too effective at staying on target.
- Reduced turret speed (60->30)
- Disruptor (Overclocked):
- Reduced drain vs command rooms by 75%.
- Reasoning: Command rooms could be indefinitely disabled with very few shots.
- Reduced drain vs command rooms by 75%.
- Railgun (Overclocked):
- Reduced length buff exponent (1.0->0.9)
- Reasoning: Long overclocked Railguns were too difficult to defend against.
- Reduced length buff exponent (1.0->0.9)
- Radiator:
- Heat from radiators will now heat other ships' shields instead of bypassing them.
- No longer applies heat to nearby friendly ships.
- Heat from radiators will now heat other ships' shields instead of bypassing them.
- Small/Medium Reactors (Overclocked):
- Removed bonus battery capacity when overclocked.
- Reasoning: Reduced the amount of time that overclocked reactors can supply power in excess of their generation rate.
- Removed bonus battery capacity when overclocked.
- M.R.T. Nozzle (Overclocked):
- Now generates a maximum of 1100 heat instead of scaling with thrust.
- Now generates a maximum of 1100 heat instead of scaling with thrust.
- Heat Mechanics:
- Reduced base damage resistance debuff (-0.9%->-0.6%)
- Reduced damage resistance debuff exponent (0.75->0.7)
- Reasoning: Damage increases from heat were too significant at all heat levels.
- Reduced base damage resistance debuff (-0.9%->-0.6%)
- Small Shield (Overclocked):
- Built-In Ships:
- Added 20 new Monolith combat ships: Adjudicatrix, Atlatl, Auxilia, Caestus, Derringer, Equites, Firewall, Flintlock, Gatecrasher, Halligan, Hand Cannon, Katar, Knuckleduster, Landsknecht, Partisan, Peltarion, Rainmaker, Sai, Trident, Vice
- Added 11 new Cabal combat ships: Altair, Asellus Primus, Asellus Secundus, Asellus Tertius, Camelopardalis, Ignis Ardens, Ignis Benedictus, Ignis Immeritus, Ignis Indominus, Saclateni, Taurus
- Added 1 new Cabal civilian ship: Shepherd
- Added 16 new Imperium combat ships: Agrippa, Anhinga, Aplomado, Buteo, Charlemagne, Ferruginous, Firewhistle, Galapagos, Groovebill, Hannibal, Jan Zizka, Nightjar, Roseate, Scipio, Woodpecker, Wryneck
- Added 1 new Imperium station: Large Imperium Trade Station III
- Added 3 new Fringe combat ships: Blackguard, Long Goodbye, Matchstick
- Added 4 new House Io combat ships: Amphisbaena, Mars, Raura, Samghata
- Miscellaneous updates to existing built-in ships.
- Added 20 new Monolith combat ships: Adjudicatrix, Atlatl, Auxilia, Caestus, Derringer, Equites, Firewall, Flintlock, Gatecrasher, Halligan, Hand Cannon, Katar, Knuckleduster, Landsknecht, Partisan, Peltarion, Rainmaker, Sai, Trident, Vice
- Career:
- Added an "Ironman Mode" advanced game option. Enabling this will restrict the player to a single save file, auto-save when exiting the game, and delete the save when all hands are lost.
- Stations that are under attack (rescue station missions) can no longer repair the player until rescued.
- Added an "Ironman Mode" advanced game option. Enabling this will restrict the player to a single save file, auto-save when exiting the game, and delete the save when all hands are lost.
- Multiplayer:
- In Arena games, junk parts will no longer linger after their original ship is destroyed. (This should improve performance.)
- The game mode filter in Online multiplayer lobbies will no longer display modes not allowed in that lobby.
- In Arena games, junk parts will no longer linger after their original ship is destroyed. (This should improve performance.)
- Ship Painting:
- Added decals: 'triangle_slanted_double' and 'resource_munition_thermal'
- The 'shape_poly_8' decal is now properly centered.
- The 'faction_io' decal now has faint horizontal stripes like the normal Great House Io faction logo.
- Added decals: 'triangle_slanted_double' and 'resource_munition_thermal'
- Graphics:
- Thermal Resonance Lances now have a different open/close animation depending on the safety toggle.
- Thermal Resonance Lances now have a different open/close animation depending on the safety toggle.
- Performance:
- Upgrade runtime to Microsoft .NET 10. This should improve overall performance by a small amount.
- Upgrade runtime to Microsoft .NET 10. This should improve overall performance by a small amount.
- Bug Fixes:
- Possible fix for audio issues on Linux/Proton. (PLEASE LET US KNOW IF THIS FIXES AUDIO ISSUES FOR YOU! If not, there's another fix I can try.)
- Possible fix for multiplayer disconnects that some players have been experiencing. (PLEASE LET US KNOW IF THIS FIXES DISCONNECTS FOR YOU!)
- Crash when starting an Elimination game with Fog of War enabled.
- Crash in single-player when detonating an Explosive Charge while also hovering the mouse cursor over another part.
- Crash in Build & Battle with 3+ players if at least one player has forfeited and a new build phase begins.
- Crash in some circumstances if an A.I. ship is destroyed while a comms window is open for that ship.
- Bullets/projectiles that died on the same tick as the game was saved would become alive again when reloading that save file, which could then lead to crashes and other bugs.
- Placing parts that changed the heat build stats would occasionally cause the game to hang.
- Rare hang when jumping to certain star systems in Career mode.
- Explosions that split ships into multiple pieces could cause multiplayer desyncs and inconsistent damage.
- Pirates attacking stations would sometimes fly to a different station, making the mission difficult/unintuitive to complete.
- Infinite money exploit by buying resources and then switching the view to another star system before the transfer is complete.
- Resources stored in trade ships was being forgotten once the trade ship went far enough from the player (went into "stasis").
- Stations far from the player (in "stasis") could become more full with trade goods than intended, leaving little room for the player to sell resources.
- On "Imagineer" difficulty, removing all crew quarters would cause the "ALL HANDS LOST" message to appear.
- Floating resources could sometimes be left behind after construction is finished.
- Visual mismatch between weapon beams (Ion Prism and Thermal Lance) and their actual hit location.
- Build mode wasn't including floating resources inside gas clouds when calculating the number of resources available.
- The quick-load hotkey was unintentionally loading the previous saved game after starting a new saved game. (It now does nothing until the game is saved.)
- Some of the build and blueprint sounds were using the wrong volume slider to control their volume.
- Possible fix for audio issues on Linux/Proton. (PLEASE LET US KNOW IF THIS FIXES AUDIO ISSUES FOR YOU! If not, there's another fix I can try.)
- Modding:
- When uploading a mod or ship pack to the Steam Workshop, you can now set the version(s) of Cosmoteer that it is compatible with. Steam will attempt to download the correct version of the item depending on which version of Cosmoteer the player has selected.
- When uploading new versions of mods or ship collections to the Steam Workshop, it is now possible to change the name, description, and preview image.
- All part components that reference triggers can now reference named triggers.
- Added an optional 'BlueprintBuffMultiplier' parameter to buff providers which modifies the blueprint and buff text values.
- Fixed NetworkTriggerReceivers not connecting to pre-existing triggers.
- Fixed crash (without an error message) when any rules file contains an invalid inheritance path.
- Fixed StatusApplication effects ignoring the 'Shields' filter.
- TileLineScoreValue components now support an optional 'OccludedByShields' parameter.
- When uploading a mod or ship pack to the Steam Workshop, you can now set the version(s) of Cosmoteer that it is compatible with. Steam will attempt to download the correct version of the item depending on which version of Cosmoteer the player has selected.
RC2 Patch Notes:
- Added 3 new Monolith combat ships: Gladiator, Ombudsman, Stormcaller
- Fixes to some of the other new built-in ships.
- Updating a Steam Workshop item will now default the name, description, visibility, and supported versions to whatever is listed on the Steam Workshop.
- Bugfix: Another possible fix for audio issues on Linux/Proton.
- Bugfix: In single-player, detonating an Explosive Charge while hovering another part would crash the game.
- Crash when overclocked shields receive negative damage.
- Possible freeze when placing parts that change heat build stats.
- Explosions that split ships could cause common multiplayer desyncs and inconsistent damage.
- Bugfix: Mods whose <mod.rules>/Actions list used inheritance would usually crash on load.
- Bugfix: Crash when booting the game on a computer that doesn't have a settings file saved yet.
Cosmoteer release candidate 0.30.3 is now available for testing! (To play this release candidate, you must opt in to test it. Please see this post for info on how to test release candidates.)
This release candidate makes quality-of-life improvements, adds new ships, improves balance, and fixes bugs.
Thanks for testing!
RC1 Patch Notes:
Built-In Ships:
Added 4 new Fringe combat ships: Hotshot, Scorcher, Smoulderer, and Stoker.
Added 11 new Cabal combat ships: Adustio, Antares, Heliogabalus, Helios, Ignis Castus, Ignis Excaecator, Ignis Immanis, Ignis Iustus, Ignis Nitidus, Ignis Primus, and Ignis Recensus.
Added 4 new Imperium combat ships: Alicanto, Ashoka, Aspatha, and Mithridates.
Added 5 new Great House Io combat ships: Lerna, Sabnock, Sargus, Vapula, and Zent.
Misc updates to existing ships.
Balance:
Point Defense (Non-Overclocked):
Increased range from 150 to 200.
Point Defense (Overclocked):
Reduced rate of fire from 15 to 11.25.
Reduced heat generation from 450 to 200.
Increased power use from 0.035 to 0.04/shot.
Decreased energy generation from 0.131 to 0.125/second.
Reasoning: Improve the number of PD that can be supported per Heat Exchanger.
Heavy Laser (Overclocked):
Reduced shield area damage from 1600 to 700.
Reasoning: Was overperforming in damage potential vs shields, especially stacked shields. (Full single-shield hits is still above non-overclocked damage.)
Railgun (Overclocked):
Reduced base damage pool from 20000 to 16000.
Reasoning: Was generally overperforming.
Large Cannon (Overclocked):
Reduced projectile speed from 195 to 170.
Reasoning: Was overperforming because bullets were too hard to dodge or intercept.
Thermal Resonance Lance:
Increased shield overload duration from 1 to 1.5 seconds.
Increased shield overload per amplification from 0.6% to 0.75%.
Increased shield overload per dilation from 12.5% to 16%.
Increased shield overload base amount from 4.4% to 5%.
Reasoning: Thermal Resonance Lance's were underperforming vs shields after prior fixes/nerfs.
Heat:
Damage resistance modifier reduced by 28%.
Reasoning: Part damage bonus from Thermal Resonance Lances was too strong.
Ship A.I.:
When A.I. ships retreat back to their origin, they will no longer turn their backs to their enemies.
User Interface:
Amplification and Dilation Pump stats now show their power usage scaling.
In multiplayer, observers are now grouped under their own "team" header in the scoreboard.
Audio:
Lots of tweaks to sound effects, including balance levels.
Reduced the volume of multiple shields enabling or disabling at the same time.
The default music and interface volumes have been adjusted to provide a better balance.
Audio levels are now limited by Cosmoteer instead of relying on the OS. (This shouldn't have any noticeable effect when playing, but should fix audio issues when recording/streaming.)
Graphics:
Fixed the 'fade_straight_triangle_half_empty` decal so that it properly matches surrounding decals.
The Great House Io faction icon now has a glow like the other icons. (Was literally unplayable.)
Bug Fixes:
On some computers with AMD GPUs, Cosmoteer would fail to start (often showing as a black box) with the error message "No suitable default monitor was found" in the log files.
Ships attacking a station would sometimes fly to the wrong station.
Missions to defeat Great House Io ships were never spawning.
It was possible to get free resources or unlimited money by buying resources and then switching to another star system before the trade was complete. (Doing so would refund the money, but then the trade would still complete upon returning to the original star system.)
Overclocked Capacitors no longer produce heat when filled by "Restock All".
Resources pre-purchased but not-yet-received from a ship or station that becomes junk weren't being refunded.
Diamond Smelters would produce diamonds even when powered off.
Following a ship in Career that goes far enough away from the player to be despawned will now properly turn the player's follow command into a move command to the target's last-known location.
Mirrored part selection now works properly for Thermal Batteries.
Viewing .rec files could sometimes freeze when jumping to another system, and would definitely freeze on the 2nd jump.
Modding:
Rules files path syntax now supports a ':' syntax which means "go to the most-derived inheritor". (This syntax is not currently being used by the vanilla rules files but will be in the future.)
Some part components (currently only resource storage components, but possibly more in the future) now support multiple triggers under different names.
All resource storage components now support a "CrewResourcesReceived" named trigger that will be triggered when they receive resources specifically from crew.
ResourceChange components now support using a specific named trigger. (Currently this is the only component, but in the near future all components that use triggers will support named triggers.)
Fixed crash in some circumstances if a translation .rules file is edited while the game is running.
Fixed NetworkPorts routing to/from NetworkNodeProxies not removing their routes when the proxy was disabled.
Fixed mods reducing part crew requirements in existing saves which could corrupt the save, causing crashes.
RC2 Patch Notes:
Updated Railgun overclock description and stats to describe its new-ish projectile fragmentation.
Bugfix: Audio was playing more loudly than intended. (Note: This reverts to the "fix" for recording/streaming issues. If you experience audio issues when recording or streaming, try lowering the in-game audio volume.)
Bugfix: Recentering blueprints would cause heat pipes to appear disconnected.
Bugfix: Heat Pipe blueprints were unintentionally rendering over part selection/hover overlays.
RC3 Patch Notes:
Translation updates for all supported languages.
Fixed a couple issues with the 'Erato' Great House Io trade ship.
Bugfix: Overclocked Point Defense was generating 1000 times more power than intended.
Bugfix: Overclocked Point Defense was not generating heat when needing less power than one recharge tick's worth.
Bugfix: Overclocked Standard, Large, Huge, and Boost thrusters had much longer thrust recovery times than intended.
Bugfix: Boost Thrusters had 25% higher power usage and heat generation while boosting than was intended.
Bugfix: Boost Thruster max power usage had been unintentionally reverted in 0.30.2; it has been un-reverted (1.38 to 1.1).
Bugfix: Certain audio effects (such as the nuke's thruster rumble) could cause annoying audio pops when stopped.
- Fixed overclocked railgun splitting projectiles causing lag/stutter.
- Fixed frequent desyncs during gameplay, especially during ship construction.
Current Release
Build 23161854
Uploaded Sep 21, 2026
System Requirements
OS
32-bit or 64-bit Microsoft Windows 10, 11, or newer
CPU
Dual-core Intel 2.0 GHz (or AMD equivalent)
RAM
4 GB RAM
GPU
1GB DirectX 10 Graphics Card or better
How to Install
1
Download all files
2
Extract the .ZIP file to a folder (use WinRAR or 7-Zip)
3
Run Bin\Cosmoteer.exe to play
Troubleshooting tips
• Run Redist/_CommonRedist installers if game won't start
• Add folder to Windows Defender exclusions
• Run as administrator
Download
Direct link available
Archive password
Needed when extracting (WinRAR / 7-Zip) — not a site login.
CRC32
6C123665
SHA-256
f42b16ef854813782cef3088ad7e842d2edd99077ab00b5f1cffd78765c20ce9
How: Right-click the downloaded file → 7-Zip / WinRAR → CRC SHA → compare with the values above.
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Download Cosmoteer: Starship Architect & Commander for PC with a direct link or via torrent. Get the full version of Cosmoteer: Starship Architect & Commander for free. Cosmoteer: Starship Architect & Commander is a Simulation released by Walternate Realities.