Stellaris Dev Diary #407 - The 4.3 ‘Cetus’ Open Beta
Date: 2025-12-11 13:05:04
Hello everyone!
4.2.4 ‘Corvus’ is in certification and may have been released by the time this goes live, with the following changes:
4.2.4 ‘Corvus’ Release Notes
Balance
- +25% volcanic world habitability for machine climate preference traits to match their minimum habitability value on Volcanic worlds.
- Replaced Food output for some specimens with one quarter as Alloy output bonus for Infernals.
- Slightly lower Unity and Research rewards for several events in the Red Giant and Cosmic Dawn Origins.
Bugfix
- The Payback origin now get the correct starting buildings as Materialist and Spiritualist
- The trait Propaganda Machines now shows the correct modifier
- When transferring planets under colonization after a war is on, if the colonizing species isn't allowed to colonize the colony is destroyed (stops forever colonization where you keep sending the new colons to the slave pits)
- Fixed leaders losing ascension related traits after species modification in some cases.
- The tooltip for Permanent Employment Civic's Reassigners say they use "Food (or equivalent)", implying they use Alloys when you are Thermophile.
- Ringworld construction and other binary/trinary restrictions correctly apply in binary or trinary hyperthermia systems.
- Replaced minor additional food upkeep for hive mind unity boosting buildings with extra Alloy upkeep.
- Fixed infernal Alloy upkeep for Voidling, purging, and non-sapient pops.
- Voidworm Troika designs can be saved.
- Voidworm Troikas are no longer created without upgrades when three large voidworms combine.
- Fixed some issues with machine empires, catalytic processing and alloy producing jobs.
- Fixed stuck in combat when the defender refuses to actually do combat.
- Volcanic Districts now improve tech weights.
- Preventing evasion to go negative from evasion against psionic modifier in combat calculation.
- Fixing abduction code setting the species correctly when checking if species can live on planet.
Performance
- Optimized string allocation in ship component modifier processing.
Stability
- Fixed random CTD with invalid ships
- Changed stack allocation to heap in particle varied values to avoid CTD:ing
- Fixed CTD due to race condition between UI and AI accessing base growth cache.
- OOS fix: Planet species caches are now stored in arrays instead of unordered sets or maps"
UI
- Shows the 25% Minimum Habitability on Volcanic worlds for Mechanical and Machine pops
But that’s not the only release planned for today!
4.3 ‘Cetus’ Open Beta
As I mentioned last week, this Open Beta is very compartmentalized so we will have the option to pick and choose different aspects to bring to the final release. This first content drop of the Cetus Open Beta includes only a partial set of Economic and Naval Change branches on top of a 4.2 base.
If all goes according to plan, 4.3 will be released to the live branches during the first quarter of 2026, but if we deem that it’s not ready yet, we’re planning to keep it in beta for longer. It’s also possible that we’ll choose to release some elements in 4.3 and then continue with a 4.4 Open Beta with the things that still need more work or polish.
The economic changes in 4.0 brought a high level of customization to planets and introduced ways of optimizing your production that did not exist before, leading to much stronger overall results. Coupled with the power creep of the Ascension expansions, empires were able to create fleets that dwarfed the end game fleets of 3.x by the mid-game.
The changes in this beta seek to ratchet that power level back significantly, restricting most sources of non-linear economic growth, in order to bring us to a more balanced level overall. Our pass is not yet complete, so I’m sure you’ll be able to find some civics, traits, or other sources that we haven’t gotten to yet - that’s okay, but expect that when we’re done we’ll have adjusted those as well. Some other changes are still in a work-in-progress state, waiting for some code support to make them work the way we want them to. Helping us find things that we may have missed or display excessive synergies and highlighting them will be very helpful.
Internally, we nicknamed this branch “The Reckoning” before it got its constellation name, since the fifty weeks of being overpowered were coming to an end.
Cetus Design Goals and Philosophy
We’re not trying to recreate the economic level of 3.x in this branch - we’re looking for where the baseline of the 4.x economy should be. We believe that this is at a level that is much lower than the 4.0-4.2 level, and that there are parts of Stellaris that haven’t been an interesting challenge for quite a long time. There’s not much incentive in doing a special project to pacify hostile Space Fauna, for instance, if an early game fleet can casually erase them from existence.
We wanted to reduce the number of ships in the game to both improve performance and to make the ships you have feel more valuable. If you have 20 full fleets moving around in a doomstack, each individual battleship you may have is just another number.
A popular mod multiplies the power and cost of ships to improve performance. It did accomplish both of those goals, but we desired a system that we believed would better fit both early and late game. We came to the conclusion that as long as the changes were consistent across the entire playing field, the economy and ships did not absolutely necessitate equal power increases to achieve the desired results. Economic output and fleet power will be significantly lower than what you’re used to, and some things that were previously trivial threats may now be a real obstacle.
In earlier dev diaries, I mentioned that I experimented with a system where naval hulls would tier up into advanced hull types. This did reduce end game ship counts and made individual ships more impactful, but we found a few drawbacks with the experiment. The importance of tech was increased even more than it already was, and there were “growing pains” moments when converting fleets up to the next tier that we thought might be interesting, but were more annoying than fun.
So far we’ve enjoyed the challenges posed by the following variant more:
The Naval Changes
The Cetus Open Beta is decoupling Naval Capacity from The Corvette Standard™. Just like how in the pop rework this gave us more granularity with jobs, this gave us the design space to do things like give Frigates their own spot in the lineup partway between Corvettes and Destroyers, and let us move Bioships to their own scale. Starting Naval Capacity has been increased to 40, and you’ll still (typically) start with three Corvettes, but they’ll take more Naval Capacity than before. This does make it easier to maintain Power Projection, but building a massive fleet is a much larger undertaking, and individual fleets have a handful of each class of ship instead of an uncountable blob of overlapping polygons.
Here’s a spreadsheet excerpt that shows tentative Naval Capacity, Hull, Cost, and Upkeep for various ships. Costs and (especially) Upkeep are notably higher than before. Frigates are now faster (moving at Destroyer speed instead of Cruiser), sturdier, get another Aux slot, and use Destroyer-grade reactors instead of Corvette-grade. Titan Perdition Beams (and similar weapons) deal collateral damage to entire fleets. (This may be changed in future Open Beta updates to something like hitting 500 Naval Capacity worth of ships in the system instead, if it seems to incentivize fleet splitting too much.)
Systems Designer @Gruntsatwork warned that based on his experience playing Vicky, leaving The Corvette Standard would lead to inflation.
Juggernauts now have 10 shipyards (and the logistics reducing aura they already have).
Harbingers have an unusual Utility slot progression but we’re currently okay with that.
These are probably completely overpowered but we’ll see.
Torpedoes have been rebalanced around these numbers and require more power (compensated on Frigates by their larger reactors).
Economic Changes
Economically, the 4.3 ‘Cetus’ Open Beta aims to deflate non-linear growth and push the game towards flatter, more controlled economies.
Goals of these changes were to make more modifiers matter, decrease the outliers, and create a leaner, more deliberate economic landscape. Some aspects of gameplay were too easy to circumvent or pin at maximum values such as empire size, happiness, and stability, while other systems such as unemployment were generally unenjoyable and did not add value to the game. Many modifiers have been returned to provide smaller, more focused bonuses or penalties, and during our economic pass we tended to favor job efficiency over raw output.
There have been some significant changes to how Automation and Fallen Empire Buildings function. They’re now job specific and Fallen Empire buildings are the only source of Specialist Job Automation.
Partial passes have been done on Origins and Ascensions, but I expect that we’ll be tweaking things and continuing passes for the next couple of months.
What Are We Looking For?
We’d like feedback on what you think of these changes. Where have we gone too hard, what do you like, what have we missed, and so on. As I’ve mentioned, this is still an early build and we’ll be iterating on it until it releases. If (and when) you find something that’s grossly out of line with the rest of the game balance, let us know so we make sure it’s looked at.
Is the challenge level appropriate? Are there more sliders that we should add to galaxy generation, or changes we should make to the base game difficulties?
We've done up a feedback form so that we can get everyone's feedback in the one place, you can find it here.
Please note: This feedback form will be changed for each Open Beta update to ensure we're getting the latest information. Feel free to fill it out every time it comes out.
Open Beta Patch Notes
Okay, here we go. Note that some of the changes in the branch are not explicitly listed here, and are covered by general notes (Like “Many sources of Unity production have been reduced.”):
4.3 ‘Cetus’ Open Beta Patch Notes 2025-12-11
Balance
- The Dimensional Fleet Astral Action has been adjusted to the reduced general fleet sizes.
- Summons a number of Escorts equal to the number of Astral Rifts you have explored, and Cruisers equal to half that number, rounded down.
- Ship Naval Capacity usage has changed significantly.
- Corvettes: 5[list]
- Frigates: 8
- Destroyers: 10
- Cruisers: 20
- Battleships: 40
- Titans and Bio-Titans: 80
- Juggernauts and Colossi: 100
- Maulers: 4/6/8
- Weavers: 8/12/16
- Harbingers: 16/24/32
- Stingers: 32/48/64
- Most ships (including Space Fauna and Event Ships) in general have 5x the Naval Capacity usage they used to.
- Nanite Swarmers are size 1[list]
- TODO: Teeth of the Eater will likely take Naval Cap while you are not at war.
- Increased base and modified Vivarium capacity to work with new numbers
- Galactic Nemesis Marauding ships have 20% less naval capacity usage than their size would normally require. (Corvettes: 4, Destroyers: 8, Cruisers: 16)
Titan Perdition Beams and Ancient Ruination Glare now deal collateral damage to other ships.
[*]Armor and Shields have been rebalanced, and now higher tiers also add a small amount of Armor or Shield Hardening as appropriate.
[*]These grant (tier - 1)% Armor or Shield Hardening
[*]Higher tier Ship and Component costs and upkeep have generally been increased.
[*]Crystal Hull plating now also grants flat damage reduction.
[*]Crystal-Infused Plating:
- S: 50 Hull, -1 Damage[list]
- M: 150 Hull, -2 Damage
- L: 450 Hull, -4 Damage
Crystal-Forged Plating:
[*]S: 100 Hull, -2 Damage
- M: 300 Hull, -4 Damage
- L: 900 Hull, -8 Damage
Frigates are now faster and sturdier, moving at Destroyer speed instead of Cruiser, have +1 Utility and Aux Slot, and use Destroyer sized reactors
[*]Base Hull for ships have been adjusted.
[*]The multiplicative damage bonus Torpedoes and Torpedo-like weapons gain has been reduced to 20% of their former values because ship sizes are 5x larger. (Effectively no change.) The maximum bonus has been increased.
[*]Many sources of Empire Size modifiers have been reduced.
[*]The base amount of Empire Size generated by pops has been halved.
- Especially things that reduce Empire Size from Pops down to 0.
- The base amount of Empire Size generated by colonies has been increased to 20.
Effects and modifiers that granted jobs per pop have been replaced with static job numbers.
[*]After a review of Unemployment mechanics, we felt that they did not add significantly to the game.
[*]All unemployed pops now demote to Civilian (or Maintenance Drone, as appropriate) at the end of the month.
- Removed the "Rising Unemployment" event chain.
- Living Standards have been adjusted.
- All living standards now include information for Slaves, just in case you find some way to get them unusual and unexpected standards like Utopian Abundance.[list]
- Happiness penalties on lower living standards now apply to Civilians.
Removed Demotion Time bonuses as they’re no longer relevant.
[/list][*]Reduced most job-based sources of research, but also reduced tech costs by half. This indirectly improves space-based deposits.
[*]Many buildings and modifiers that increased job output have been reduced.
[*]Most stability bonuses have been reduced to one half to one third of their previous values.
[*]The intention of this change is to make Stability generally more important and harder to pin at 100, and make things like +1 or +2 Stability effects more valuable.
[*]Most job efficiency modifiers have been reduced.
[*]Some production modifiers have been turned into job efficiency modifiers.
[*]Ethics Changes:
[*]Authoritarian:
- Worker Production bonus is now Worker Job Efficiency.
- Egalitarian
- Specialist Production bonus is now Specialist Job Efficiency.
- Pacifist
- Reduced Empire Size from Pops bonus to -10%/-20%.
Many sources of Unity production have been reduced.
[*]Bubbles (and other misnamed variants) no longer uses up Naval Capacity
[*]Many traits that reduced Housing usage have been rebalanced.
[*]Increased base naval capacity to 40
[*]Rebalanced Naval Capacity techs
[*]Increased the power usage of Torpedoes and Energy Torpedoes on standard ships
[*]Colony Designations now universally add Job Efficiency to their appropriate Jobs.
[*]Planetary Ascension now increases the Designation effect by 10% per tier instead of 25%.
[*]Obsessional Directive now grants +15% Artisan Drone Job Efficiency, and increased Consumer Goods storage. The Commodities Consolidation situation now grants Artisan Drone Job Efficiency and adds Unity production to Artisans (instead of all Unity).
[*]Ascension situations now progress slower.
[*]Exceptions: Synthetic Fertility and Endbringers. Tick-tock.
[*]Resettlement costs are now the same across all strata. (Since demotion is now immediate at the end of the month, this prevents an undesired element of micromanagement where you would want to fire any pops you wanted to resettle.)
[*]Anchorages now give +5 Naval Capacity, +3 with a Naval Logistics Office.
[*]Special planetary deposits are now 4x more common.
[*]The Subterranean Contact Zone now provides job swaps for traders or logistic drones.
[*]Removed inappropriate researcher jobs from planetary features which provided them.
[*]Made some unique planetary features more interesting.
[*]Subsidy Edicts now grant +20% or 10% Efficiency and +0.5 Trade Upkeep
[*]Readjusted bonuses from Genesis Guides civics
[*]Halved the modifiers from the Genesis Preserves
- Added an on action to remove the Preserves if you reform your government
- Reduced rewards from colonising from 500 Unity and 25 Influence to 250 Unity and 5 Influence
- Reduced rewards from uplifting from 1000 unity to 250 Unity and 5 Influence
- Ensured that a Genesis Preserve is created only if one does not already exist.
- Unity from Jobs modifier from the Genesis Monument is decreased to 10% if you don't have the civic
- Updated various checks to check for all variants of the civic instead of just the version for regular individualist empires
- Set the strata for newly spawned pre-sapients to actually be pre-sapient instead of No Category
Adjusted some more upkeep reductions on buildings to match the new economic model.
[*]More strategic resource production has been moved to the strategic resource producing district specializations. Significantly reduced the amount given for free by the strategic resource deposits without the specialization.
[*]Tankbound Production Overseers now generate 2 Engineering Research instead of Unity, and grant +2% efficiency and +200 Amenities. They are only granted by Urban districts (or as Clerk swaps).
[*]Automation Building Changes:
[*]Assembly Patterns and Construction Templates are now Tier 2 and 4 technologies.
- Automation Buildings are now job specific, and no longer increase their upkeep based on district count.
- Automated Worker or Simple Drone Jobs increase their upkeep by 4 Energy per 100 jobs.[list]
- Automated Specialist or Complex Drone Jobs increase their upkeep by 8 Energy per 100 jobs.
- Automated Elite Jobs increase their upkeep by 12 Energy per 100 jobs.
Fallen Empire Buildings:
[*]Are now Planet Limit 1 and automate 25% or 50% of relevant Specialist jobs or 75% or 100% of relevant Worker jobs. These are the only sources of Specialist automation in the new economic system.
- Exceptions:[list]
- Dimensional Replicator now produces 10 of each Strategic Resource, Dimensional Fabricator now produces 25 of each Strategic Resource and 5 of each Rare Resource[list]
- Sky Dome / Empyrean Dome, Shrinkspace Depot / Extra-Dimensional Depot functionality remains the same.
Adjusted costs, upkeep, and build times of Fallen Empire buildings.
[/list][*]Fallen Empires now gain +100% Automated Workforce Efficiency
[*]Awakened Empires gain an additional +500% Automated Workforce Efficiency
[*]Soldiers are now Specialist (or Complex Drone) jobs with 1 Alloy upkeep.
[*]Polytechnic Mentors now grant Miners engineering research. The bonuses they grant have been reduced to +0.1.
[*]Naval Capacity:
[*]Naval Capacity values adjusted.
- Anchorages now have Trade Upkeep equal to the Naval Capacity they are providing.
The Nano-Corpses deposit now yields alloys, not rare crystals.
[*]The Mountain in the Sky deposit from the Gravity Storm has been rebalanced, but allows construction of a unique district specialization.
[*]The Aquaculture district specialization now provides 50 jobs of each type, not 75.
[*]Anglers no longer produce additional food.
[*]Anglers and Pearl Divers are now swapped on wet worlds, regardless of district specializations.
[*]Factions have 50% reduced output during the first ten years of the game (when factions normally do not exist).
[*]Parliamentary System now grants +20% Faction Output but has +50% disapproval for unmet demands.
[*]Increased base Unity production of empires from 5 to 10.
[*]Civics that provide politician job swaps (Technocracy, Merchant Guilds, Exalted Priesthood) now provide additional jobs to relevant buildings.
[*]Overtuned origin no longer has early access to genetic ascension.
[*]The bonus pop growth and amenities provided by Genomic Researcher jobs from selecting Cloning traditions and choices during Biomorphosis have been moved to the Genomic Research Facility building. The amount of amenities granted has been increased to 500.
[*]Rebalanced all council positions that gave flat resources to jobs.
[*]Dark Consortium Civic now has a beefier Dark Matter Deposit on game start.
[*]Pass on Edicts. Many now affect Efficiency.
[*]Knights are now considered Soldiers instead of Bureaucrats and Researchers.
[*]Strong, Very Strong, and Weak traits now also affect Soldier efficiency.
[*]Adjusted effects of Commander and Scientist governors.
[*]Battle Thralls now get a bonus to Soldier efficiency.
[*]Disruptors now start with 50% shield and armor bypass at tier 1 which increases to 80% at Psionic Disruptors. They now also deal +25% damage against shields.
[*]Increased Unity production and Consumer Goods upkeep of Politicians.
[*]Commander Starting Level civics: Swapped Commander XP Gain for Commander Upkeep Reduction on Distinguished Admiralty. Added Commander Upkeep Reduction to Warbots and Strength of Legions.
[*]Machine Capital Buildings (tier 2 or higher) now also add Coordinator jobs.
[*]Reduced the power of the council positions for Chosen civics.
[*]The Corporate Authority now has +1 Envoy instead of +1 External Leader Pool.
[*]Clustered Capacity (Virtuality) now gives +75% Virtual Pop Job Eff and -10% per Colony. (Was +175%, -25% per Colony)
[*]Cybernetic Traits no longer have energy upkeep.
[*]The Cybernetic and Limited Cybernetic traits now swap half of the base food (or equivalent) upkeep for energy upkeep.
[*]Media Conglomerate now gives early access to factions, but replaces faction unity output with trade output.
[*]Rebalanced many species traits
[*]Erudite
- +30% Researcher job efficiency -> +20% Researcher job efficiency[list]
- Rationale: Number too big
Fertile:
[*]+30% Pop Growth Speed -> +20% Pop Growth Speed
- Rationale: Number too big
Vat Grown:
[*]+33% Organic Pop Assembly -> +25% Organic Pop Assembly
- Rationale: Number too big
Existential Iteroparity
[*]+30% Pop Growth Speed -> +20% Pop Growth Speed
- Rationale: Number too big
Numistic Administration:
[*]+33% Trader job efficiency -> +25% Trader job efficiency
- Rationale: Number too big
Dark Matter Engines
[*]+40% job efficiency -> +20% job efficiency
- Rationale: Number too big
- Upkeep per 100 Pops: 0.02 Dark Matter -> 0.03 Dark Matter
- Rationale: Makes the cost matter more
Living Metal Augmentations
[*]Upkeep per 100 Pops: 0.01 Living Metal -> 0.03 Living Metal
- Rationale: Makes the cost matter more
Biomimetic Assembly:
[*]+50% Replicator job efficiency -> +20% Replicator job efficiency
- Rationale: Number too big
Matrix Trading
[*]+50% Trade job efficiency -> +20% Trade job efficiency
- Rationale: Number too big
- Upkeep per 100 Pops: 0.01 Rare Crystals -> 0.02 Rare Crystals
- Rationale: Makes the cost matter more
Mote-Powered Tools
[*]Upkeep per 100 Pops: 0.01 Volatile Motes -> 0.02 Volatile Motes
- Rationale: Makes the cost matter more
Exotic Fuel Consumption
[*]+10% job efficiency -> +10% Specialist & Complex Drone job efficiency
- Rationale: General nerf and harmonisation with the next trait
- Upkeep per 100 Pops: 0.04 Exotic Gases -> 0.05 Exotic Gases
- Rationale: Makes the cost matter more
Volatile Mote Reactor
[*]+30% Habitability -> +10% Worker & Menial Drone job efficiency
- Rationale: General nerf and harmonisation with the previous trait
- Upkeep per 100 Pops: 0.02 Volatile Motes -> 0.05 Volatile Motes
- Rationale: Makes the cost matter more and harmonisation with the previous trait
Rare Crystal Exterior
[*]+20% Metallurgist job efficiency -> +30% Habitability
- Rationale: Flavour text makes this more appropriate for habitability
- Upkeep per 100 Pops: 0.02 Rare Crystals -> 0.05 Rare Crystals
- Rationale: Makes the cost matter more and harmonisation with the previous traits
The Arcology Project and districts on Ecumenopoleis now cost alloys instead of minerals
[*]Partial pass done for some advanced authorities. These will continue in future Open Beta drops.
[*]Dictatorial Cybervision now grants a flat Cyborg job efficiency bonus and scaling Stability for Enforcers.
- Physiological Transcendency now gives +2 Unity per 100 Politician jobs instead of +3 Unity per 100 Elite pops.
- Dictatorial Cybervision and Homogenous Submission now give Governing Ethics Attraction instead of Authoritarian ethics attraction.
Reduced difficulty based scaling on the Grey Tempest and Khan. Roaming Tempest fleets may not always have a Mothership on lower difficulties. (Garrison fleets are unchanged.)
[/list]Bugfix
- Removed remaining references to pre-4.0 strategic resource harvesting jobs that were converted into job swaps.
AI
- AI empires will now prefer to have three or fewer underdeveloped colonies before colonizing the next one. (Underdeveloped is defined as having under 1000 pops.)
UI
- When using Observer mode, Mercenary Enclaves no longer appear in the regular empire list, they're at the end classified as "Minors"
- Unemployment information in the central bar of the planet view has been replaced with information on planet Denizens (Civilians or Maintenance Drones)
Modding
- Added faction_demands_met_mult and faction_demands_unmet_mult which affect faction approval or disapproval of met or unmet demands.
Later today we're going to put the first part of the 4.3 ‘Cetus’ Open Beta branch up on Steam as cetus_open_beta. We plan to update this branch again next week.
To access a Stellaris beta, go to your Steam Library, right-click the game, and select "Properties". From there, choose the "Betas" tab, and in the "Beta Participation" dropdown menu, select the cetus_open_beta beta branch from the list.
What’s Next?
Next week’s dev diary will feature any updates we make to the beta next week and will be our end-of-year review before the winter holidays.