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Territories can be upgraded with a variety of infrastructure to improve the Population output output and Pop happy.png happiness of their pops, as well as its accessibility and defensibility, at the cost of Wealth gold. Investing in infrastructure can significantly improve a country's Wealth income, Manpower.png manpower, Research points.png research, and more, and is generally most effective in more highly populated territories.


A wide variety of different buildings can be built in territories to give a wide variety of local modifiers, such as improving pop Population output output and Pop happy.png happiness, adjusting the ratio of pop classes, driving Pop assimilation.png assimilation and Policy religious conversion.png conversion, increasing the local Population capacity population capacity, adding Fort level fortifications to the area, and more. The buildings available depend on the territory's rank, with different sets available to Territory settlement.png settlements and Territory city.png cities/Territory metropolis.png metropolises; some of the Territory settlement.png settlement buildings are also restricted based on the trade good that the territory produces.

Every building has an associated Wealth gold cost and Time build time, which are modified by the Build cost.png build cost and Build time.png build time modifiers, respectively. Each territory can only build one building at a time, though it is possible to make a queue of buildings to construct. Once it is built, buildings do not cost any maintenance or upkeep. Any building in any owned territory can be torn down instantly at any time, which returns 1/4th of the its Build cost.png build cost to the treasury (regardless of when or by whom the building was built).


Building Province modifiers Cost Cost Time Time Territory rank
Training Camp Training Camp
  • Manpower.png +10% Local manpower
50 180 days City
Fortress Fortress
  • Fort level +1 Fort level
100 915 days City/Settlement
Foundry Foundry
  • Starting experience +5% Starting experience
  • Local output +1% Population output
50 180 days City


Building Province modifiers Cost Cost Time Time Territory rank
Market Market
  • Local base trade routes.png +2.5% Local base trade routes
50 180 days City
Tax Office Tax Office
  • National tax +10% Local tax
50 180 days City
Academy Academy
  • Research points.png +7.50% Local research points
  • Noble ratio +1% Local noble desired ratio
50 180 days City


Building Province modifiers Cost Cost Time Time Territory rank Requirements
Granary Granary
  • Global food capacity.png +200 Provincial food capacity
50 180 days City
Library Library
  • Noble happiness +4% Local noble happiness
  • Noble ratio +2% Local noble desired ratio
50 180 days City
Court of Law Court of Law
  • Citizen happiness +3% Local citizen happiness
  • Citizen ratio +6% Local citizen desired ratio
50 180 days City
Forum Forum
  • Freeman happiness +3% Local freemen happiness
  • Freeman ratio +6% Local freemen desired ratio
50 180 days City
Mill Mill
  • Slave output +3% Local slave output
  • Slave happiness +4% Local slave happiness
  • Slave ratio +6% Local slave desired ratio
50 180 days City
Temple Temple
  • State religion happiness +3% State religion happiness
  • Policy religious conversion.png +1.00 Pop conversion speed
50 180 days City
Theater Theater
  • Integrated culture happiness +3% Integrated culture happiness
  • Pop assimilation.png +1.00 Pop assimilation speed
50 180 days City
Aqueduct Aqueduct
  • Population capacity +4 Population capacity
50 180 days City
  • Has at least Civilization.png 30 civilization value

Settlement Only

Building Province modifiers Cost Cost Time Time Territory rank Requirements
Barracks Barracks
  • Population capacity +20% Population capacity
  • Manpower.png +20% Local manpower
  • Freeman happiness +8% Local freemen happiness
  • Freeman ratio +15% Local freemen desired ratio
120 180 days Settlement None
Slave Estate Slave Estate
  • Population capacity +20% Population capacity
  • Monthly food.png +50% Local monthly food modifier
  • Slave output +30% Local slave output
120 730 days Settlement None
Mine Mine
  • Population capacity +20% Population capacity
  • Goods from slaves.png -5 Slaves needed for local surplus
120 730 days Settlement Produces Base metals, Iron, Marble, Precious metals, or Stone
Farming Settlement Farming Settlement
  • Population capacity +20% Population capacity
  • Goods from slaves.png -5 Slaves needed for local surplus
  • Monthly food.png +50% Local monthly food modifier
120 730 days Settlement Produces Fish, Grain, Livestock or Vegetables
Tribal Settlement Tribal Settlement
  • Population capacity +20% Population capacity
  • Tribesman output +30% Local tribesmen output
  • Tribesman happiness +8% Local tribesmen happiness
120 730 days Settlement None
Provincial Legation Provincial Legation
  • Migration speed +75% Pop migration speed
  • Pop assimilation.png +0.20 Pop assimilation speed
120 180 days Settlement None

Building slots[edit]

Local building slot.png The number of buildings that can be built in any particular territory is limited by that territory's number of building slots. Each building takes up 1 slot, including those under construction, and no buildings can be built in a territory that has filled up all its slots. Territories that have more buildings than their number of permitted slots - for instance, after losing population during a sack - will lose any buildings over the limit.

Territory settlement.png Settlements always have 1 building slot and this cannot be increased, so they can only ever have a single building (though settlement buildings are in general stronger than other buildings). Building slots become relevant when settlements are upgraded to Territory city.png cities, which gives a base of 2 extra building slots and an additional 1 for every Population.png 10 pops in the city. If a city is further upgraded to a Territory metropolis.png metropolis the base number of building slots is increased to 4. Other important sources of building slots include:

  • +1 for the Country capital.png country capital
  • +1 for Holy Site.png holy sites
  • +1 for all Territory city.png cities with the Invention.png Urban Planning invention (Civic power.png Civic Advances 18)
  • +1 for all Territory city.png cities with the Military tradition.png Legacy of the Builders military tradition (Levantine and Arabian traditions)


Roads built by a Roman army.

Ability road building.png Roads can be built by Land combat.png armies to connect two adjacent territories at the cost of Wealth gold, reducing the Movement cost movement cost by 50% and effectively doubling the army movement speed between them, making them highly desirable for larger empires that would benefit from being able to move armies between their provinces more quickly. In addition to the army movement bonuses, connecting a territory to the road network also gives a minor boost to development, trade, and pop mobility, making them useful to build in highly populated developed territories as well as connecting frontier areas. Roads also appear graphically on the map as the network is built and extended, generally being most prominent on the terrain mapmode; if a road is built over a river, a bridge will appear. Unlike with buildings, roads are not associated with individual territories, but instead with pairs of adjacent territories (including possibly those connected over a strait); it is therefore possible (and common) for a territory to be a part of multiple different road segments. For every road connecting a territory to one of its adjacent territories, a territory will get the following stackable modifiers:

  • Civilization.png +0.001% Monthly Civilization Change
  • Policy religious conversion.png +2.5% Pop Conversion Speed
  • Pop assimilation.png +2.5% Pop Assimilation Speed
  • Local pop promotion speed.png +2.5% Pop Promotion Speed
  • Local pop demotion speed.png +1% Pop Demotion Speed
  • Migration attraction +0.05 Migration Attraction
  • Migration speed +0.05 Pop Migration Speed
  • Local base trade routes.png +0.05% Local Base Trade Routes Modifier

There are two ways to build roads - one for countries with Military tradition.png Italic traditions, and one for countries with any other military tradition set. Once a road is built, it cannot be removed or destroyed, even if the territories it connects are completely depopulated.

Regular roads[edit]

Most countries need to reach at least Civic power.png Level 5 of civic advances to begin building roads.

Roads can be built using the Build road Build Road unit ability toggle, which can be activated if all of the following conditions are met:

  • The unit is an Land combat.png army
  • The army has at least Land combat.png 10 cohorts
  • The army is not in combat, moving, or exiled
  • The army is in a territory that is owned by the current country, or by one of its Vassalized.png subjects
  • The army either has no commander, or its commander is loyal (i.e. has at least Loyalty.png 34 loyalty)

When the Build road build road toggle is on, road construction will begin when the unit moves from one territory to another, as long as both territories either owned and controlled by the army's owner or one of their Vassalized.png subjects, or are uncolonized (including uninhabitable territories, though not impassable terrain). When the army arrives in that other territory, if the two territories do not already have a road between them, the road will be instantly built at a base cost of Treasury.png 50 gold. This cost is affected by the Build roads cost modifier.png build roads cost, given only as a -25% modifier from the Invention.png Gromatici invention (Civic power.png Civic Advances 15).

WhileBuild road building roads, the following modifiers are applied to the army:

  • Morale.png −25% Morale of Armies
  • Army movement without roads −70% Army movement without roads
  • Army maintenance cost.png +120% Army maintenance cost

The toggle will be turned off if the army becomes ineligible to build roads, or if the army finishes moving to a new territory without a road on the traversed connection and the country does not have enough money to build a road.

Roman roads[edit]

Countries with Military tradition.png Italic military traditions need to pick the Roman Roads tradition from the Roman path to unlock road construction, even if they have already meet the requirements for normal road construction. Otherwise, Build road building Roman roads is largely the same as building regular roads, with the main differences that the road-building army can be smaller, requiring only Land combat.png 5 cohorts, and that each road costs only Cost 25 gold per territory connection. However, note that this cost is not affected by the Build roads cost modifier.png build roads cost modifier.

As well, a reduced set of modifiers is applied to the road-building army, without the increased maintenance cost or morale penalty:

  • Army movement without roads −70% Army movement without roads


See also: Siege

Fortification.png Forts can be built in territories to block the advance of enemy armies and protect important cities and strategic points from being easily captured. The size of a fort is determined by its Fort level fort level, with 1 as the minimum and 0 indicating the lack of a fort in the territory; all Country capital.png country capitals start with Fort level 1 fort level by default, and every Fortress fortress building adds Fort level 1 further fort level. Note that this means that Territory settlement.png settlements are generally restricted to a Fort level fort level of 1, with only Territory city.png cities and Territory metropolis.png metropolises able to support larger forts. Each fort level gives -1 to siege progress and provide the base Garrison garrison of 1000 per fort level, adjusted by the Garrison garrison size modifier. An besieging army needs to be at least 4 times as large as the garrison to begin a siege, and when a fortress falls (or a new fort level is built), its Garrison garrison will need to be replenished at a rate of 10% of the max garrison per month. Forts with a high fort level will therefore need both a large commitment of forces and a significant amount of waiting to successfully take, and can be a potent defensive measure at important chokepoints.

In addition to the opportunity cost of taking up a building slot, every Fortification.png fort also costs a base of Wealth 0.50 gold in maintenance each month, adjusted by the Fort maintenance cost.png fort maintenance modifier. Fortifications are therefore quite costly, particularly for smaller countries, and it is often a good idea to remove extraneous forts that no longer serve any menaningful defensive purpose if the maintenance costs are becoming an issue.

One of the main effects of a Fortification.png fort is that it prevents enemy armies from being able to occupy the territory after the base occupation time of 15 days, but instead requires the attacker to successfully siege or assault the Fortification.png fort before the territory can be occupied. In addition, Fortification.png forts exert an zone of control over the adjacent territories, restricting enemy movement and controlling nearby territories. An Land combat.png army that enters a hostile zone of control will not be able to progress further, and must instead either proceed to the Fortification.png fort and besiege it or return to the territory they came from - in this way, a line of Fortification.png forts one or two territories apart can completely block an enemy army from progressing past it, and can be useful along contested frontiers or to protect valuable core areas. As well, any hostile territory within a zone of control of a Fortification.png fort that is not being besieged will have occupation progress as though an army was occupying it, unless an army on the same side as the current controller is currently in the territory; if a territory lies in the zones of control of multiple hostile forts, it will continually switch occupation every several days between each side. Territories within a friendly zone of control will also not lose Civilization.png civilization value when occupied by Barbarian power.png barbarians, making them useful to build near barbarian strongholds. Zone of controls are fully active for not only owned and controlled forts within the country, but also controlled forts within enemy nations, making it possible for a counteroffensive into previously occupied territory to be blocked by a country's own occupied forts.

Border forts[edit]

See also: Colonization

A country with the Military tradition.png Italic military tradition Castra (from the Support path) can have an army build a Construct border fort border fort in an owned frontier or neighbouring uncolonized territory. An army can do this action if it meets all the following conditions:

  • The unit is an Land combat.png army
  • The army has a loyal commander (defined as Loyalty.png 34 loyalty or higher).
  • The army is not in combat, moving, sieging, or exiled.
  • The army has at least Land combat.png 5 cohorts, including at least one that is not Loyalty gain chance.png loyal to anyone.
  • The territory the army is in:
    • Doesn't already have a Fortress fortress
    • Is uncolonized, or owned by the current country and borders a foreign (not uncolonized) territory
    • Has a free Local building slot.png building slot
    • Borders an owned and controlled territory
    • Is not next to any other owned territory with a Fortress fortress

When the ability is activated, the country loses Manpower.png 3000 manpower and builds a Fortress fortress in the territory. The country then gains ownership of the province if it was previously uncolonized, in which case the territory will also gain a Freemen freeman pop of the primary culture and religion. Finally, one random cohort becomes Loyalty gain chance.png loyal to the commander, unless the general is the ruler of a non-republic, in which case the country gains Tyranny 1 tyranny instead. This ability can notably be used to colonize territories even if there is no neighbouring territory with a dominant integrated culture and state religion.