Stellaris Dev Diary #409 - The 4.3 ‘Cetus’ Open Beta Continues
Massive performance optimizations for event processing and ship modifiers alongside a balance pass for the Cutholoid encounter and Scorched World Heralds civic.
Key Changes
- 1Massive performance boost: Event scope parameters now up to 83x faster
- 2Ship modifier calculations optimized to be 68% faster
- 3Cutholoid ambush fleet power requirement reduced to 600
- 4Fixed multiplayer Resync button functionality
- 5Fixed Starbase Resource Silo bug that reduced empire capacity during upgrades
- 6Scorched World Heralds restricted from granting citizenship to non-Thermophiles
- 7Under One Rule Luminary trait count corrected
- 8Three technologies added as Gateways for Rural District Specialization
All Changes
🚀Performance(10)
- changeEvent System: Optimized event parameter storage, reducing heap allocations for 95% of EventScope uses.
- changeEvent System: AddOrUpdateScopeParameter is now 71x faster, eliminating performance spikes.
- changeEvent System: CreateEventScope is now 48x faster with eliminated performance variability.
- changeEvent System: AddScopeParameter is now 83x faster.
- changeEvent System: GetScopeParameter is 35% faster with median time reduced by 84%.
- changeShips: Ship CalculateModifier is now 68% faster.
- changeArmies: Army CalculateModifier is now 5.3% faster.
- changePlanets: Uninhabited Planet DailyUpdate is 3-5% faster.
- changeScripting: Improved Scripted Trigger caching for better efficiency.
- changeEngine: String allocation optimized to be 76% faster.
⚙️Gameplay Systems(4)
- buffTechnologies: Field Modulation, Eco Simulation, and Geothermal Fracking are now marked as Gateway technologies for Rural District Specialization.
- changeScorched World Heralds: Scorched World Heralds civics now explicitly mention that diplomacy with other Thermophiles is possible.
- changeRogue Servitors: Rogue Servitors alien life discovery text updated to be tonally appropriate.
- fixMachine Species: Blocked the First Robot timeline event for machine species.
⚖️Balance(2)
- nerfScorched World Heralds: Scorched World Heralds can no longer grant Full Citizenship or Residence status to conquered non-Thermophile pops.
- buffCutholoid: Reduced the minimum fleet power necessary to trigger the fight with the ambushing Cutholoid to 600.
🛠️Bug Fixes(7)
- fixMultiplayer: Fixed the Resync button in multiplayer menus.
- fixCaravaneers: Fixed scoping issues with random events occurring when neighboring Caravaneers.
- fixUnder One Rule: The Luminary for Under One Rule now receives the correct number of traits for their level.
- fixGalactic Crucible: Fixed the Galactic Crucible not triggering notifications or event choices after capture in specific post-war situations.
- fixScion: The Scion origin now correctly blocks the Scorched World Heralds civic.
- fixStarbases: Starbase targeting owner country modifiers now trigger a country recalculation as intended.
- fixResource Silo: Upgrading a Starbase with a Resource Silo no longer incorrectly lowers the total empire resource capacity.
Summary
Performance Overhaul
This update introduces significant engine-level optimizations, specifically targeting event scope parameters and modifier calculations. Some code paths are now up to 83x faster, resulting in a ~10% reduction in frame processing time and smoother gameplay during the mid-to-late game.
Gameplay & Balance
The 'Cetus' Open Beta continues with adjustments to the Scorched World Heralds civic, restricting citizenship for non-Thermophiles. The Cutholoid ambush has been made more accessible with a lower fleet power requirement, and several technologies have been reclassified as gateways for Rural District Specialization.
Bug Fixes & Stability
Key fixes include the restoration of the multiplayer Resync button and a correction for Starbase Resource Silos that previously caused empire-wide resource capacity to drop during upgrades.
More from Stellaris
- 4.3.2 Open Beta is now on stellaris_test [checksum 171a]Mar 20, 2026
- Stellaris 4.3.1 hotfix release (checksum f646)Mar 19, 2026
- Stellaris Dev Diary #412 - 4.3.0 ‘Cetus’ Preliminary Release NotesMar 11, 2026
- Stellaris 4.3 "Cetus" Open Beta Updated (2026-03-06)Mar 6, 2026
- Stellaris 4.3 "Cetus" Open Beta Updated (2026-03-04)Mar 4, 2026