update · August 13, 2026
Stellaris 4.5 'Cygnus' Open Beta Update 5 Refines Factions and Starbase Weapons
Stellaris Open Beta Update 5 for the 'Cygnus' 4.5 branch brings sweeping improvements to starbase weapon modules, faction behaviors, and automated ship design logic. The patch also tackles numerous bug fixes regarding nomad empires, purge vassals, and UI tooltips.
Paradox has pushed Update 5 to the Stellaris 4.5 'Cygnus' Open Beta branch. This iteration focuses heavily on weapon module customization, faction attraction mechanics, and cleaning up a wide assortment of automation and nomad-related bugs.
Starbase and Weapon Module Overhauls
Starbase, Orbital Ring, and Waystation weapon modules are now specific to weapon types such as lasers, mass drivers, swarmer missiles, particle launchers, psionic torpedoes, and strike-craft hangars. Each module is gated behind its matching technology and automatically upgrades to your latest tier. Additionally, the Starbase Weapon Preference policy now supports Explosive and Strike Craft options.
Faction and Ethic Tweaks
The daily faction update has been optimized to evaluate pre-triggers and join rules once per update. Promoting or suppressing a faction now has a tangible impact on its attraction, and factions with the same ethics can be adjusted independently. Furthermore, the Supremacists no longer spawn in Pacifist empires at all, and pops from other species can now join the Supremacists at a reduced attraction rate.
AI and Fleet Composition
Empire fleet composition is now driven entirely by active fleet doctrines and weapon preferences, moving away from older personality- and civic-based ship ratios. Once unlocked, crisis and ascension hulls are favored in automated fleet builds.
Nomad and Subject Adjustments
Nomad empires can now benefit from specific accords like the Composer of Strands and End of the Cycle. Purge vassals now handle pops according to their Overlord's playstyle when utilizing ascension perks like Mechromancy or Galactic Nemesis, rather than defaulting to simple purging.
Why this patch matters
Update 5 gives players deeper control over military configurations and internal politics, rounding out the 'Cygnus' beta with crucial under-the-hood performance gains.