Crusader Kings III 1.20.0.3
Governments
All 20 government types: the holdings a ruler of each must hold, the rules and modifiers that come with it, its colour on the government map mode and the law groups it uses.
Crusader Kings III has 20 government types: Feudal, Republic, Clan, Tribal, Wanua, Mercenary Company, Military Order, Monastic Order and 12 more. Patch 1.20.0.3, from game/common/governments.
This section as JSON: /raw/governments.json
FeudalCastle holdingsUnder the Feudal Government Form, a Liege gives their Vassals Land to govern in exchange for Levies and Taxes, regulated by individual Vassal Contract between Vassal and Liege.
RepublicCity holdingsRepublican Government is an unplayable Government Form where an elected citizen rules for life — the Government Form of burghers and merchants.
ClanCastle holdingsClans are a Government Form in which the amount of Levies and Taxes given to a Liege by their Vassals is determined by the Aptitude of said Liege's Tax Collector. Clans also make use of House Unity.
TribalTribe holdingsTribal realms have stunted county Development, cannot advance past Tribal Era Innovations, cannot construct new Holdings, and are usually unable to change their Succession Law.
WanuaTribe holdings · All Under HeavenThe Wanua Government shares weaknesses with the Government, but also have reduced Domain Limit and Vassal Limit. While they use Gold to construct Buildings and recruit Men-at-Arms, they earn very little Gold from Buildings.
Mercenary Companyno holdings of its ownMercenary companies roam the lands in search of employment, and take up arms for the highest bidder. Loyalty is essential to a good reputation, but it only lasts until the end of their contract. The mercenary leader is chosen from within the company's ranks.
Military Orderno holdings of its ownThe holy warriors of the orders have dedicated their life to fighting infidels and serving their faith. They may hold castles given to them by pious landholders. The order leader is chosen within the order ranks.
Monastic Orderno holdings of its ownThe monks and nuns of the monastic orders dedicate their lives to prayer, learning, and the spread of their rite. They may hold temples granted to them by pious landholders. Upon the leader's death, the order passes to the member most learned in the faith.
AdministrativeCastle holdingsAdministrative is a Bureaucratic Government Form that appoints Characters as Governors, to manage and preside over land, called Provinces, on behalf of their Liege.
Adventurerno holdings of its ownAn Adventurer is an Unlanded Character who leads a Camp.
NomadicNomadic Settlement holdings · Khans of the SteppeNomadic Rulers graze County Fertility to grow their Herd. They can use Herd as Nomadic Horde, which can be upgraded to Men-at-Arms. They have a Nomadic Capital.
HerderHerder Camp holdingsHerder realms are removed from all aspects of rulership. They do not command Armies, own Buildings, create Alliances, or declare Wars. When Nomads Migrate a Holding, herders will slowly replenish the local County Fertility by virtue of their smaller flock.
CelestialCastle holdingsCelestial is a Bureaucratic Government Form in which the Liege appoints characters as Governors, of which there are two types, Civilian and Military.
MandalaTemple Citadel holdings · All Under HeavenUnder the Mandala Government Form, the Domain Limit and amount of Direct Vassals are limited. Instead the Liege and Suzerain are reliant on Tributaries for expanding their realm. 
Meritocratic KhanateCastle holdings · All Under HeavenMeritocratic Khanate is a Bureaucratic Government Form similar to the Celestial and Meritocratic, but originating from a Nomadic Government Form. The Liege appoints characters as Governors, of which there are two types, Civil and Military. They still maintain Tributaries, enforce Obedience, and have a higher maximum Dread.
MeritocraticCastle holdings · All Under HeavenMeritocratic is a Bureaucratic Government Form similar to Celestial, in which the Liege appoints characters as Governors, of which there are two types, Civil and Military.
RitsuryōCastle holdings · All Under HeavenRitsuryō is a type of Bureaucratic Government unique to Japan.
SōryōCastle holdingsSōryō is a type of Feudal Government unique to Japan.
TheocracyTemple holdingsTheocracy is a Government Form available for some Faiths depending on Doctrines. They are usually lead by a Head of Faith or a Landed Realm Priest. A Bishop might also become an Independent Theocratic ruler in their own right.
EcclesiasticalTemple holdingsEcclesiastical is a Theocratic Government Form held by Christian Clergy Rulers, such as Bishops and Archbishops.
Source: game/common/governments and the English localisation, Crusader Kings III 1.20.0.3. The bar on each card is the government's map colour from the files. See also laws.