Paradox has detailed a new Ideologies system for Stellaris, part of the upcoming Willpower expansion. The feature was introduced in Stellaris Dev Diary #436, published on the official Steam news feed on October 15, 2026, and written by Gary Morris, DLC Director for Willpower from Abrakam Entertainment.
Fanatic factions can push a regular empire to adopt an official Ideology, which then spreads from colonies and exerts diplomatic pressure. Morris, known as Atmaz, called Ideologies “the most deeply integrated system” the team has developed for Stellaris and “our most ambitious project to date.”
The diary covers regular empires only. Paradox explicitly deferred gestalt empires to a future dev diary, so the current information applies to standard empire management and faction play, following the Stellaris 4.5 Cygnus update from September.
How Ideologies Emerge From Fanatic Factions
Willpower adds Fanatic Factions with two behavioral changes. They receive increased resource output, but they also carry a higher unmet-demand disapproval rate. A faction linked to a Fanatic Ethic begins fanaticized, and a faction can also become fanaticized over time if it holds high support and approval for a long period.
When a fanaticized faction emerges, the player can choose to adopt an official Ideology from the Manage Faction menu if conditions are met. Adoption costs a monthly Influence upkeep. The player decides the timing.
Spread, Authority, and Tenets
An Ideology spreads from population sources such as colonies. A new map mode shows this footprint, and spread intensity is modified by Unity production, Amenities, Trade, and other factors. More happy and productive ideological followers make the Ideology spread faster and farther.
The area under an Ideology’s reach reduces Claim and Starbase Influence cost for systems outside the player’s borders and lowers Starbase upkeep. Each Ideology receives a flag with unique emblems per Ethic type, and players can rename it.
Forming an Ideology turns the player into an Ideological Authority with inherent bonuses. The Authority status is retained as long as no other empire adopting the same Ideology reaches a higher strength level and diplomatic weight.
Only the Ideological Authority can codify Tenets. This requires gaining Ideological Strength. Players normally receive three Tenet slots, and each slot scales upward in Intensity. Tenets can be Reformulated for an Influence and time cost. Most Tenets are locked to specific Ethics, and certain Civics and Origins can generate their own.
The diary names Open Stars Sovereignty as one Willpower Civic. It is available to Fanatic or Absolute Xenophiles.
Pops convert naturally under Ideological Reach, and entire empires can adopt the player’s Ideology. That adoption increases Authority bonus modifiers and improves relations. Aggressive methods of forcing adoption also exist, though the diary does not detail them in this entry.
Ideologies Mechanics at a Glance
| Mechanic | Confirmed behavior |
|---|---|
| Fanatic Factions | Increased resource output and higher unmet-demand disapproval; can start fanaticized or fanaticize over time with high support and approval. |
| Ideological Reach | Grows from colonies; spread uses Unity, Amenities, Trade, and modifiers; reduces Claim and Starbase Influence cost and Starbase upkeep outside borders. |
| Ideological Authority | Granted on forming an Ideology with inherent bonuses; lost if another empire reaches higher strength and diplomatic weight. |
| Tenets | Only the Authority can codify them; three slots scaling in Intensity; Reformulation costs Influence and time; most locked to Ethics. |
| Ideological Momentum | Tracks recent Ideological Strength; negative momentum risks negative modifiers or Ideological Revolts, opposing Ideologies, or colony secession. |
The reveal continues a busy stretch for Paradox, which also has the Hearts of Iron IV energy rework in open beta.
Confirmed and Unconfirmed
Confirmed: Paradox detailed fanatic factions, Ideology adoption with monthly Influence upkeep, map spread, Ideological Authority, Tenets, Ideological Momentum, and the Open Stars Sovereignty Civic. Empires sharing an Ideology view the player more favorably.
Unconfirmed: Paradox has not provided a release date or window for Willpower, a price for the expansion, numeric values for Influence upkeep, Tenet modifiers, or Ideological Strength thresholds. The source also does not explain how Ideologies work for gestalt empires because that is deferred to a future dev diary.
