Federations and the Galactic Community are the systems Stellaris players most often treat as passive income: join something, collect a bonus, keep expanding. That reading survives until a vote fails, a member walks out, or a Custodianship you wanted goes to somebody else. Both are meters with a clock attached.
This guide covers the rules as documented for PC version 4.3, the version the Stellaris wiki’s Federation and Galactic Community pages are marked verified for at the revisions cited below; Paradox’s dev diaries supply the intent where the wiki only lists numbers.
What this covers: how the six federation types, centralization and cohesion constrain each other, and how the Senate’s recess-and-session rhythm moves a resolution chain toward the Custodian and Emperor tracks. Why it matters: each track is a commitment. Centralization costs cohesion you must pay back with an Official, and Proclaim the Galactic Imperium permanently ends your empire’s ability to form or join a federation. Who should read this: players who would rather spend influence on a plan than discover the cost after the vote passes.
Federations Are Six Different Commitments
A federation is a supranational alliance whose members automatically defend each other as under a Defense Pact, but must agree to offensive wars as a group. Members build no border friction, build trust to a cap of +100, and share 10% of their victory score. The price is a −15% cut to every member’s energy output, and leaving grants a decaying −200 opinion with everyone still inside. A federation disbands at one member or none.
Creating one requires either The Federation tradition or the Federation Code technology. Two routes bypass that: a rebellion against the Galactic Imperium, or the option offered shortly after a War in Heaven begins.
The type you pick decides which perks exist and which laws unlock early. Changing type is possible at any time, but it resets the federation level to 1 — the most expensive click in the system.
| Type | Who can form it | Level-1 effect | What it forecloses |
|---|---|---|---|
| Galactic Union | Any empire except Barbaric Despoilers | −50% cohesion loss from diverse ethics | No specialist perk |
| Trade League | Corporate authority, Corporate Dominion, Merchant Guilds, or Commerce tradition (Federations DLC) | Trade League trade policy | A military or research identity |
| Research Cooperative | Materialist, Machine Intelligence, or Discovery tradition (DLC) | Free and automatic research agreement with all members | Early fleet scaling |
| Martial Alliance | Militarist or Fortification tradition (DLC) | +25% ship build speed, +100 ship and army starting experience | Economic and research perks |
| Hegemony | Authoritarian, Rogue Servitor, or Domination tradition (DLC) | Members cannot freely leave; they can gain the Secede casus belli; centralization requirements are reduced | Voluntary exit |
| Holy Covenant | Spiritualist or Harmony tradition (DLC) | +10% monthly unity | Non-spiritualist members’ bureaucracy buildings, which swap to Temples |
Two restrictions are easy to miss: Barbaric Despoilers can create only a Martial Alliance or a Hegemony, and every type except Galactic Union sits behind the Federations expansion, which shipped on 2020-03-17 with the free 2.6 patch that added Envoys and Diplomatic Stances.
Paradox’s Federation Q&A says “Federations are (theoretically) alliances between equals”, which is why independent diplomacy is required to found one. For a federation-friendly start, the origin and civic builds that open diplomacy trees early are the cheapest way in.
Cohesion Is the Real Federation Currency
Cohesion runs from +100 to −100 and does three jobs. Each 10 points above zero adds +1 federation XP per month, up to +10; each 10 below adds −1, down to −10. Each 4 points above zero adds +1 acceptance for changing federation laws, and each 4 below subtracts the same. Below 90, acceptance for raising Centralization drops by a flat 50. That is the trap: the moment cohesion slips, the law you need to fix it is the law you cannot pass.
Immediate hits:
- −100 when any member joins or leaves, including when an empire integrates a subject that was also a member
- −50 when the federation type changes, and −10 when Centralization changes
- −10 when a vote fails, and −5 for any other law change
Monthly drags: −0.5 for each opposed ethics pair, −0.15 multiplied by the number of different ethics minus three, and −0.25 for each member. Cohesion can only be increased by assigning an Official to the federation, at +1 per month per leader level, and AI empires always assign one. Drop below your level’s XP requirement and fail to climb back within 90 days, and the level downgrades, removing those perks.
| Centralization | Required level | Monthly cohesion | Member intel cap |
|---|---|---|---|
| Minimal | 1 | 0 | +10 |
| Low | 2 | −1 | +20 |
| Medium | 3 | −2 | +30 |
| High | 4 | −3 | +40 |
| Very High | 5 | −4 | +50 |
Enacting any option also adds −10 cohesion on top of its monthly cost. The Q&A confirms this is deliberate: “High Centralization will have a larger negative impact on monthly Cohesion, which means more Envoys will need to be assigned to maintain it.”
Centralization then unlocks the levers that make a federation feel like a state. Fleet Contribution transfers 10%, 20% or 30% of members’ naval capacity and yields a federation fleet of 200, 400 or 600 capacity, with no maintenance and a Titan limit of up to four that does not touch members’ own Titans. Required centralization varies by type: a Martial Alliance or Hegemony can take Low contribution at Minimal, while a Holy Covenant or Research Cooperative needs Medium before Low is even available. Each option above None costs −5 cohesion.
The Senate Has a Clock
The Galactic Community is a body where each member empire votes on laws that bind all members. Any empire with communications to a member may join or leave; joining after formation costs 100 influence. Leaving costs 100 to 500 influence depending on Empire Size, bars re-entry for 20 years, and applies a permanent −30 opinion penalty with current members. Genocidal empires cannot join.
Formation needs an empire that is not a Gestalt Consciousness or Fanatic Purifier to have communications with at least 70% of the other empires, with at least three non-genocidal empires in the galaxy; at least three must agree.
The Senate alternates between two phases:
- A Recess lasts 720 days and votes on nothing. When it ends, the proposal with the highest diplomatic support enters Session.
- A Session lasts 1,440 days. Supporters and opposers add their diplomatic weight to each side; abstaining adds nothing. Every empire may change its vote every 4 months. The higher total wins.
A Galactic Council member can declare a proposal an emergency measure every 20 years, ending the recess immediately. A Custodian can end a session once half its time has passed, which the wiki prices at 200 influence.
Diplomatic weight is the currency inside those 1,440 days: 15% of economic power, 2.5% of fleet power, 40% of technology level, plus pops contributing twice their happiness plus one, ignoring political power. Assigning an Official to the Community adds +10% per leader level. That pop term is why a happiness collapse is also a diplomatic collapse: the pop growth, jobs and migration system feeds straight into your Senate weight.
Favors are the override. Each costs 10 influence and lets you borrow up to 10 favors from a member voting against you, each adding 10% of that member’s diplomatic weight to your side without reducing theirs. Only 100 favors may be used per resolution. The AI never spends its own favors and always opposes resolutions that would put it in breach of Galactic Law.
Resolution Chains: One Proposal Each
Resolutions are the laws themselves, and the queue is scarce. Any member may propose one, but each member can have only one on the list. Proposing costs 100, 150, 200, 250 or 300 influence depending on the tier; withdrawing does not refund it, and a repeal costs as much as the original. The proposer gains +5% diplomatic weight for six years if it passes and −5% if it fails.
Passage is serial. Most lists run five resolutions deep and must be passed in order, alongside the option to repeal the current top-level resolution. Sanction lists are only three deep. Once a resolution passes, another from the same list — including its repeal — cannot be proposed until a resolution from a different list has been voted on. That rule is why a coalition that wants one reform can be stalled by an opponent who wants any other.
The wiki’s summary line describes five resolution trees holding at least two lists each, but the same page then documents more than eight lists, including Galactic Commerce, Industrial Development, The Greater Good, Ecological Protection, Unchained Knowledge, Divinity of Life, Mutual Defense and Rules of War, plus separate lists for Sanctions, Denouncements, the Galactic Market, Pre-FTL Stances, Space Fauna and Politics Traditions. Treat those as the working map. Sanctions cost only 25 influence to propose against an empire in breach of Galactic Law or under denouncement, and only Council members can escalate them to their final two levels.
The Custodian Track: Council, Then Emergency Powers
The route starts with the Council. Form Galactic Council costs 300 influence and requires the Community to be at least 20 years old. Members are drawn from the highest diplomatic weight every 20 years and receive +20% diplomatic weight. After it exists, the Galactic Reforms list opens.
| Reform | Influence | What it buys |
|---|---|---|
| Change Council Size (1–5) | 200 | Council membership count |
| Enable Council Veto Power | 150 | A veto every 5 years for 300 influence, barring that proposal for 15 years |
| Remove Council Veto Power | 250 | Ends the veto |
| Enable / Remove Council Denouncement Power | 150 / 250 | Council denouncements on or off |
| Permanent Council Seat | 300 | A targeted empire always sits on the Council |
| Nominate Custodian | 300 | Elevates a Council member |
| Unseat Custodian | 200 | Returns the Custodian to the Council |
Nominate Custodian cannot target subjects or empires holding a crisis ascension perk, and is withdrawn if the target becomes ineligible while queued.
Once passed, the Custodian receives +5 monthly influence, +30% diplomatic weight replacing the Council bonus, −50% to both emergency measure cooldown and veto cost and cooldown, open borders across every member, the ability to change the Galactic Focus for 100 influence without a resolution, and the ability to freeze any resolution so it cannot be voted on. A Custodian also cannot be targeted by subjugation casus belli. Dev Diary #200 prices the freeze at 200 influence for four years and notes the Custodian gains intel such as other members’ relative fleet power.
The term is 30 years, after which the Custodian returns to the Council. Custodian-unique resolutions cost 200 influence each, and Remove Custodianship Term Limit can only be used once. The Galactic Defense Force, established by its own Custodian resolution, is limited to a total Naval Capacity of 400 that resolutions can expand, pays no upkeep, and is designed and commanded by the Custodian. If there ceases to be a Custodian, the GDF becomes an independent entity until a new one is established.
Persuasion is the real gate: Dev Diary #200 states the AI “is more likely to vote for a Custodian when there is some sort of crisis going on,” which can include a Marauder crisis or an endgame crisis. Waiting for a crisis to nominate costs far less goodwill than forcing the vote in a quiet galaxy.
The Emperor Track: What It Forecloses
Proclaim the Galactic Imperium is listed among the Custodian’s unique resolutions, gated on the Custodianship having no term limit. It does not reform the Senate; it ends it, and the Community becomes the Imperium.
Most of what changes is subtraction:
- Every Imperium member leaves any federation it belongs to and cannot form or join new ones. This clause makes the track irreversible in practice.
- The Custodian becomes Galactic Emperor, shifting ethics toward Fanatic Authoritarian, government toward Imperial, and gaining the Galactic Sovereign civic plus the ability to upgrade the capital’s planetary capital into an Imperial Palace. Custodian perks remain in force, the Emperor cannot be attacked by Imperium members, and empires cannot leave.
- When an outside empire attacks a member, the Emperor can join the war for +20 Imperial Authority and +250 opinion with the defender, or refuse at the same cost.
- The Galactic Council becomes the Imperial Council, and Galactic Reform resolutions are replaced by Imperial Council ones only the Emperor can propose.
Imperial Authority decides whether the Imperium holds. Officials can be assigned to raise or lower it by 0.1 per month each, and an espionage operation exists to weaken it. At 100 or above, all members join the Emperor in defensive wars. Below 50, members can use the Spark Rebellion espionage operation against the Emperor. If the empire leading the Imperium is conquered or destroyed, the Imperium reverts to the Galactic Community, with Imperium-specific resolutions repealed.
Choosing a Track
| Track | Entry cost | What it gains | What it forecloses |
|---|---|---|---|
| Stay a member | Join 100 influence; leave 100–500 | Vote weight, favors, resolution perks | Independent foreign policy while laws bind you |
| Build the Council | Form Galactic Council, 300 influence | +20% diplomatic weight; veto, denouncement, emergency measure | Nothing directly; the 20-year rotation can unseat you |
| Custodian | Nominate Custodian, 300 influence | +5 influence/month, +30% diplomatic weight, session control, freeze, GDF | A 30-year term that ends without a second resolution |
| Emperor | Term-limit removal plus Proclaim the Galactic Imperium | Immunity from member attacks, no exit, Imperial Council | Every federation, permanently |
The Custodian track is a spending problem; the Emperor track is a deletion problem. A federation you left to become Emperor is not recoverable, because Imperium members cannot form or join one. Players building around ascension paths should settle the Emperor question before committing the perk — the 4.4 Pegasus patch coverage is where to check whether a later update moved these numbers.