Sins of a Solar Empire II: Harbinger Expansion Arrives September 3, 2026

After 20 years of intrigue, the great enemy of the Vasari is revealed, ushering in new gameplay mechanics, ships, structures and more.

PLYMOUTH, Mich., Aug. 6, 2026 /PRNewswire/ -- Today, Stardock announced the release date for the upcoming Expansion for Sins of a Solar Empire II, Harbinger. The Vasari have spent generations running, and they have warned anyone who would listen about what was behind them. On September 3, 2026, their time runs out and players will finally discover the greatest threat they've ever faced: the Eidolon.

Fighting for planets, trade routes, culture, or wealth is not the Eidolon way. Working behind the scenes, the Eidolon spread corruption wherever they go. Their technology shroud entire worlds to fuel their advance, and they strike from the shadows with cloaked fleets, forcing every other empire to fight for survival on unfamiliar terms.

Features

The Eidolon rewrite the rules of galactic conquest with systems built around corruption, secrecy, and control:

• Planetary Transformation: The Eidolon spread corruption across the galaxy to empower themselves and their worlds. As populations fall under the Eidolon's influence, their planets gain corruption over time. Once a world has fully fallen, it can be shrouded, greatly expanding the upgrades that planet can support.
  
  
• Unit Corruption: Corruption empowers Eidolon units in combat as well as weakens them. As an Eidolon ship gains corruption, its hull dwindles while its offensive power increases. Enemy forces can become infected by corruption, giving the Eidolon another advantage.
  
  
• Null Weapons: Eidolon weapons are far more advanced than the other factions; and can negate shields and spread corruption against enemies.
  
  
• Cloaked Ships: Subterfuge is one of the sharpest weapons of a great enemy, as on the Kalizaeth Profaner support capital ship. New cloaking and detection systems let the Eidolon appear and vanish at will, enabling hit-and-run tactics that reward patience and punish anyone caught off guard.
  
  
• Psionic Abilities: The Eidolon possess psionic abilities that allow them to seize control of lesser beings and drive Vasari ships into madness firing on friend and foe alike.
  
  
• Phase Echoes: Sometimes the dead don't die. Eidolon units infused with corruption may refuse to die and carry on the onslaught.
  
  
• Unit Animation System: A new unit animation system brings the Eidolon and other faction units to life with recoiling cannons, expanding factories, hangar bay doors and more.
  
  
• Discover more about the Sins universe as you explore ancient technology and research new Eidolon capabilities.

"Sins of a Solar Empire fans have been waiting for this reveal for a very long time," said Brian Clair, Director of Publishing at Stardock. "The team has been focused to make sure we don't disappoint and give players a new, unique experience."

Sins of a Solar Empire II: Harbinger is available to wishlist now on Steam and will be available to purchase at launch on Epic Games Store and sinsofasolarempire2.com. The Harbinger Expansion will be available standalone for $29.99 and is included as part of the Premium Edition for $99.99 or as part of the Sins of a Solar Empire II: Content Pass for $59.99. Follow Sins II and learn more at www.sinsofasolarempire2.com.

About Stardock Entertainment

Stardock is a pioneer in the strategy gaming genre headquartered in Plymouth, Mich. that has been developing and publishing strategy and simulation games since 1993, starting with the original release of Galactic Civilizations. Stardock's recent hits include Sins of a Solar Empire, Ashes of the Singularity, Elemental: Fallen Enchantress, and Offworld Trading Company. Learn more at www.stardock.com.

Media Contact:

Colin Regan
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Zebra Partners

SOURCE Stardock Entertainment