Source note: Part 1 of the Crusader Kings 3 reference. Every government type, authority law, doctrine, and mechanic below is verified against the official Paradox CK3 wiki (current version 1.18–1.19). DLC attribution is cross-checked against the Roads to Power announcement and the wiki. Part 2 covers culture, ethos, and traditions; Part 3 covers how to choose and the DLC roadmap.

Crusader Kings III (2020) is a grand-strategy RPGRPG. Role-Playing Game — a game built around character progression, story, and player choices. in which you play a medieval dynasty across generations — not a nation, a character. Your two foundational build choices at the start of a reign are your government (how your realm is ruled) and your faith (your religion’s doctrines, tenets, and relationship to every other faith). These two systems, more than culture or geography, define what you can and cannot do.

What it covers: Every government type, authority law, and the faith system — doctrines, tenets, fervor, holy sites. Why it matters: Government and faith are the two foundational build choices gating laws, succession, and diplomacy. Who should pick this: CK3 players planning a campaign, especially Roads to Power administrative or adventurer runs.


The government axis

CK3 governments come in three types:

  • Landed: require a title.
  • Domicile: a home base, not a title.
  • Non-dynastic: not playable.

Your government gates your laws, your succession, your vassal obligations, and your casus belli.

Landed governments (playable)

GovernmentDLCCore mechanicsBest for
TribalBaseTribal Authority law; Subjugate/Conquest CBs; raids; pays for men-at-arms in Prestige; stuck on tribal innovations and Confederate Partition successionEarly-game expansion; migrating tribes
FeudalBaseCrown Authority law; create holdings/cadet branches; title succession laws; feudal contracts with vassalsThe “standard” medieval realm; long-term stability
ClanBaseLike Feudal but vassal taxes/levies scale with opinion; powerful vassals want alliances; realm named after dynasty if you’re a dynasty headMuslim and dynastic realms; opinion-driven play
AdministrativeRoads to Power (2024)Appointed Governors; Influence resource; Noble Families/Estates; State Faith; Appointment/Acclamation succession; Emperor can seize Theme armiesByzantine-style bureaucracy; court intrigue

Domicile governments (playable)

GovernmentDLCCore mechanicsBest for
AdventurerRoads to Power (2024)Landless; a camp domicile; fulfill contracts across the map; earn gold/prestige/fame; settle down to claim a kingdom laterRags-to-riches; roaming playstyles
Herder(nomadic)Tend a flock; tied to steppe life; can become Nomadic on startSteppe nomads

Non-dynastic governments (not playable)

GovernmentNotes
RepublicMayors/merchant republics; elected, so the ruling dynasty changes — not playable. As a vassal, a republic pays 20% taxes and 10% levies.
TheocracyRuled by clerics; elected/appointed; taxes and levies scale with your Level of Devotion.
Holy OrderReligious mercenaries that can also hold land; you can hire their armies for free against other-faith enemies.
Mercenary CompanyRoam seeking employment; leader chosen from within the company.

Authority laws — the lever of control

Every realm has an authority law that determines how much control the ruler has over vassals. Increasing it costs Prestige scaled to realm size (capped at 900) and has a cooldown.

  • Crown Authority (Feudal/Clan): Autonomous Vassals → Limited → High → Absolute. Gates title revocation, vassal retraction, succession laws, and vassal taxes/levies.
  • Tribal Authority (Tribal/Wanua): Disparate Tribes → Limited → High → Absolute. Gates the Adopt Feudal/Clan Ways decisions and imprisonment.
  • Administrative Authority (Administrative): Decentralized Realm → Limited Administration → Centralized Bureaucracy → Absolute Autocracy. Gates vassal limits, administrative tax contribution, and feudalization cost.
  • Celestial Authority / Japanese Authority (DLC): variants for the Celestial, Meritocratic, Ritsuryō, and Sōryō governments.
  • Dominance (Nomadic): Weak → Limited → High → Absolute → Unrestricted. Scales with Herd; gates migration distance, domain/vassal limits, and the path to becoming the Greatest of Khans.

The takeaway: authority is the single most important law to push early. Higher authority means more taxes, more levies, the ability to revoke titles, and — for Tribal rulers — the gate to reforming into Feudal or Clan.

The Administrative government in depth (Roads to Power)

Administrative is the biggest addition since launch and the reason the Byzantine Empire finally plays like Byzantium:

  • Noble Families & Estates: every house head gets a Noble Estate (a villa + six building slots) independent of any title — your power base even when out of office.
  • Influence: a new resource spent to appoint/revote Governors, take control of Imperial (Theme) armies, and steer succession. Earned by landing family members, schemes, estate buildings, and Governor Issues.
  • Governors & Themes: Duchy/Kingdom titles become Themes/Catepanates; their rulers are Governors with a Governor trait that scales their tax-raising and army command. Governors can’t declare war on each other — they scheme for Influence and favor instead.
  • State Faith: an official faith of the empire; vassals convert to it more easily and away from it less easily, suppressing heresies.
  • Appointment & Acclamation succession: Emperors spend Influence to appoint heirs; or the realm acclaims the most influential candidate.
  • Ceremonial Monarchy: (at Empire rank) a Regent Ruler and a Ceremonial Monarch co-rule, modeled on the Japanese imperial court.

Playing as the Byzantine Emperor under Administrative government is fundamentally different from a Feudal start: you manage a web of squabbling Governors rather than landed vassals, and Influence — not just Prestige — is the coin of the realm.


The faith axis

Every character follows a faith — a denomination of one religion, which belongs to one of three religious families (Abrahamic, Eastern, Pagan). Faith is the other half of your build: it sets your doctrines, your tenets, your virtues and sins, your holy sites, and how every other faith views you.

Religious families & faith hostility

Three families determine baseline hostility between faiths:

FamilySame religionSame familyOther family
AbrahamicHostileEvilEvil
PaganAstrayHostileEvil
EasternAstrayAstrayHostile

Each faith also assigns every other faith one of four stances — Righteous, Astray, Hostile, Evil — which set opinion penalties, intermarriage rules, and whether you can wage holy wars or use holy orders against them. Pluralist doctrine halves these penalties; Fundamentalist doubles them.

Doctrines (the rules of the faith)

Each faith has a set of doctrines — the laws of the religion — across several categories:

  • Main doctrines: View on Gender (Male Dominated / Equal / Female Dominated), Religious Attitude (Fundamentalist / Righteous / Pluralist), Clerical Tradition (Theocratic / Lay Clergy), Head of Faith (None / Spiritual / Temporal), Theism (Monotheist / Polytheist).
  • Marriage doctrines: Marriage Type (Monogamous / Polygamous / Consorts & Concubines), Divorce, Bastardry, Consanguinity (who you can marry).
  • Crime doctrines: which traits are virtues, sins, accepted, shunned, or criminal (e.g., Same-Sex Relations, Adultery, Deviancy, Witchcraft, Kinslaying).
  • Clerical doctrines: Clerical Function, Clerical Gender, Clerical Marriage, Clerical Appointment, Funerary Tradition.
  • Special doctrines: religion-specific rules (e.g., Sunni/Shia succession doctrines for Islam; Ecumenism for Christianity; Jizya for most Muslim faiths; the Mandala-relevant polytheist doctrine).

Tenets (three big bonuses per faith)

Every faith has three tenets — large, unique bonuses that can change how the faith views others and grant powerful effects. Examples from the wiki: Armed Pilgrimages (Catholicism) makes holy wars 20% cheaper and lets the Head of Faith call a Great Holy War once Fervor is over 75; Communion unlocks indulgences and excommunication; Pluralism halves faith-hostility penalties.

Virtues & sins

Each faith lists traits it considers virtuous or sinful. A Virtue grants +10 same-faith opinion and +1 monthly piety; a Sin does the reverse. Tenets can add to or change these lists. Religion-level virtues/sins stack on top of faith-level ones.

Fervor & heresies

Fervor (0–100) measures how righteous adherents believe a faith is. High Fervor faiths convert better; low Fervor faiths get converted. The Head of Faith needs Fervor ≥ 75 to call a Great Holy War. If Fervor drops below 40, a heresy can break out — 10–25 counties and at least one Duke convert to another faith within the same religion. This is the main internal threat to a large faith.

Holy sites

Most faiths have 5 holy sites (Hindu faiths have 7). Controlling a holy site grants a permanent bonus to every follower of that faith (e.g., Catholicism’s sites — Jerusalem, Vaticano, Cologne, Canterbury, Santiago — give +1 Stewardship and +10% development speed when a Catholic controls Rome). Holy sites are pilgrimage destinations and are required to create a Head of Faith or reform a pagan faith.

Creating & reforming faiths

  • Create a new faith: once per lifetime, at peace, for a large piety cost scaled to how far the new tenets/doctrines are from your current faith. Ruler, close family, and realm capital convert; vassals may follow.
  • Reform a pagan faith: control ≥3 holy sites and spend large piety. Reformation removes the “Unreformed” tag (a big deal — unreformed faiths can’t use feudal/clan ways, convert worse, and can’t build holdings).
  • New/reformed faiths inherit the holy sites of the original and grant a Holy Legend seed.

How government × faith define a CK3 build

These two axes interact to shape your playstyle:

  • Tribal + unreformed pagan: expansion via Subjugation/Conquest CBs and raids; pay men-at-arms in Prestige; reform your faith and adopt Feudal/Clan Ways to “graduate.”
  • Feudal + Catholic: long-term stability; Crown Authority + title succession; Armed Pilgrimages cheapen holy wars; the Pope is a lever (and a rival).
  • Clan + Muslim: opinion-driven vassal management; dynasty-named realm; Jizya lets you tax non-Muslim vassals; Mandala-style governance if polytheist.
  • Administrative + Orthodox (Byzantium): Governors scheme for Influence; State Faith suppresses heresy; you appoint heirs and seize Theme armies.
  • Adventurer + any faith: landless contracts across the map; build a camp; settle down to claim a kingdom by merit.

What’s next

Part 2 covers the culture axis — the five cultural pillars (Heritage, Language, Aesthetics, Martial Custom, Ethos), all seven ethos, the tradition system, hybrid and divergent cultures, culture splits, and cultural acceptance.

→ Continue to Part 2: Culture, Ethos & Traditions

← Back to Part 3: How to Choose + DLC Roadmap


SOURCES

All government types, authority laws, doctrines, and faith mechanics are drawn directly from the Paradox CK3 wiki (v1.18–1.19). DLC attributions (Roads to Power = Administrative + Adventurer, 2024) are confirmed by the official Paradox announcement and the wiki.

Part 2 takes up the culture axis — pillars, ethos, traditions, and hybrids — and Part 3 turns all three references into a chooser plus the DLC roadmap through Chapter V (2026). With Roads to Power’s Administrative and Adventurer governments now tabled above, you already have the two newest ways to start a campaign.

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