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Imperator: Rome tutorial #4 - economy and trade.



The main source of income over time in Imperator are Taxes and Commerce.

Output efficiencyEdit

Output efficiency factors summed up and then applied multiplicative to the base output of each social class. Output efficiency is the sum of:

  • Happiness of class
  • Code of Rights (freemen) +2.5%
  • Right to be Heard (citizen) +5%
  • Tyranny: (slaves)+0.5*Tyranny Score
  • some trade goods surplus in province (hemp: +2% for slaves)
  • Province policies (Harsh Treatment -32% (scales ??), Local Autonomy -60%)
  • (Province Investments: reduction for 2 years, needs verification)
  • (Province Procurator investment +4%, needs verification)
  • Capital Region +10% all classes
  • Capital Province +10% all classes
  • Capital Territory+10% all classes
  • Dominant culture is not primary culture -20% (all classes)
  • Settlement -25%
  • Religion: Mercury +10%
  • Governor Traits (Harsh: slave output +10%)
  • Governor Bonus 2.5% per finesse point, (needs verification)
  • Foundry +1%
  • Harsh Taxation: national slave output +10%

Tax IncomeEdit

The provider of tax income are pops belonging to the   Freemen   Slaves and   Tribesmen social classes. Each freeman generates 0.005 gold per month, each slave generates 0.035 gold per month and each tribesman generates 0.015 gold per month at 100% output efficiency, which is modified multiplicative with output efficiency of each social class and number of pops of each class and rounded down to the second digit.

Then a whole lot of modifiers are applied to the term to calculate the total amount:

  • Territory:
    • Each   Tax Office building adds +10% to the generated local tax todo: more than one Tax Office ?
    • -2% per unrest of Territory
    • part of output efficiency: Capital City receives a bonus of +10% (stacks with capital region bonus + capital province to +30%)
  • Province:
    • The availability of certain Trade Goods in the province (applies for all Territories)
      • Cloth +10%
      • Gemstones +20%
      • Amber +10%
    • Surplus Boni for each surplus Trade Goods in the province
      • Cloth +5%
      • Gemstones +10%
      • Amber +5%
    • Governor policy (scaled by governors finesse. Numbers are for finesse 9))
      • Acquisition of Wealth +10%
      • Bleed them Dry+30%
    • part of output efficiency: each city belonging to the Capital Province receives a bonus of +10% (stacks with capital region bonus to +20%)
  • Region
    • part of output efficiency: Each city belonging to the Capital Region receives a bonus of +10%
    • Governor's Faction, Finesse,Corruption and Traits
      • Governor's corruption contributes to unrest +corruption/20% (needs verification)
      • Governor's finesse contributes to output efficiency 2.5% per finesse point
      • Governor's wage -25%
  • State:
    • State's government type
    • State's Stability only indirectly, by increased global unrest
    • Ruler's Faction, Attributes and Traits,
    • Currently chosen National Ideas
    • Enacted Laws
    • National Tax Law (Lax Taxes -50%), Default Taxation, Harsh Taxation part of output efficiency:slave output +10%)
    • Researched Technology level
    • Purchased Inventions
    • Co-Consul -10%
    • Office
    • Events and Decisions
    • Deity
      • Pluto +0.1% per omen power

Base taxEdit

Every nation, regardless of its size or number of pops, has a base tax of 2.50, this can be affected by the modifiers listed above. Base tax is crucial for small nations' economies in the early game but becomes irrelevant when the nation expands and grows. Modfiers for base tax:

  • Laws
  • Events
  • Co-Consul -10%
  • Office



Commerce income is determined by a city's commerce value multiplied by its commerce modifiers. Commerce value can come from two sources,   citizens and Trade Routes. Citizens produce 0.01 commerce value * output efficiency per population and month. Trade routes add a base commerce value that is divided by the number of cities in the province with each city receiving the same share. Both these commerce values are then multiplied by the commerce modifiers to give you one city's commerce income.


  • Territory
    • each Marketplace +25%
    • -2% per unrest
    • Holy Site +15% (no scaling, needs verification)
    • Museion of Pythagoras 5%
  • Province
    • Province policy (all policies are scaled by governors finesse. Numbers are for finesse 9)
      • Aquisition of wealth +10%
      • Encourage trade +25%
      • Bleed them dry +20%
    • Trade routes: export and import values
  • Region/Governor (tooltips in the province window)
    • -25% governor wage
    • Governor trait Prominent +10%
  • Nation wide (tooltips in the province window)
    • +2% per ruler finesse
    • +2.5% per level of civic advances
    • Omen
      • Mercury
    • Commerce laws do not change commerce value as modifieres, but change values or numbers (in capital) of trade routes instead.


Every office or job in your country has a defined wage. A wage is always a certain percentage of your income, how high dependent on the office it is for. Character Corruption further modifies the wage of office holders.

Economic PoliciesEdit

There are also various economic policies that affects your income and expenses on a country level.


Modifies income from taxes.

Policy Bonus Drawback
Lax Taxation -1 National Unrest -50% National Tax
Default Taxation No Effect No Effect
Harsh Taxation +10% National Slave Output -20% Research Points


Modifies income from Commerce.

Policy Bonus Drawback
Free Trade +20% Export Value -15% Import Value
Trading Permits +2 Capital Trade Routes None
Transaction Taxation +20% Import Value -15% Export Value


Modifies how much you expect your subject states to pay to you.

Policy Bonus Drawback
Lax Tribute +50 Subject Opinion -33% Tribute Income from Subjects
Default No Effect No Effect
Extortive Tributes +25% Tribute Income from Subjects -50 Subject Opinion

Army MaintenanceEdit

The Monthly cost for all troops in your country.

Policy Bonus Drawback
Decreased Pay -33% Army Maintenance Cost -80% Army Morale of Non-Clan Retinues
Normal Pay No Effect No Effect
Increased Pay +10% Army Morale of Non-Clan Retinues +50% Army Maintenance Cost

Fleet MaintenanceEdit

The Monthly cost for all the ships of your country.

Policy Bonus Drawback
Decreased Pay -50% Naval Maintenance Cost -80% Naval Morale
Normal Pay No Effect No Effect
Increased Pay +10% Naval Morale +50% Naval Maintenance

Fort MaintenanceEdit

The cost to maintain all forts of your country.

Policy Bonus Drawback
Ignored Garrisons -25% Fort Maintenance -50% Garrison Size and Fort Defence
Paid Garrisons No Effect No Effect
Extortive Tributes +10% Garrison Size and Fort Defence +25% Fort Maintenance


How much the wage of offices and jobs is increased or decreased.

Policy Bonus Drawback
Reduced Wages -25% Monthly Wages for all Characters +0.25 Monthly Corruption
Normal Wages No Effect No Effect
Increased Wages -0.1 Monthly Corruption +50% Monthly Wages for all Characters


Should your country at any time find itself running a deficit this will result in a number of bad things. These can be seen at the bottom of the screen under the balance itself. Some of these events may well help you turn your economy around, but none of them come without a high price to be paid in some form.

  • Loyality Gain Change +25%
  • Monthly Political Influence -50%
  • Monthly Stability Change -0.2
  • Populist Faction Influence +0.1

Several options have a monthly change of 6.25% to happen:

  • Bad Planning
  • Deficit!
  • Desperate Measures
  • A Friend in Need...
  • Tightening the Strings
  • A Gift from the Gods
Domestic policy State Characters Attributes Culture Government Laws National ideas Rebellion Religion Technology
Economic policy Buildings Economy Population Trade Trade goods
Provinces Region Province Territories Colonization
Military Military traditions Army Siege Assault Land units Land warfare Naval warfare
Foreign policy Treaties Warfare Casus belli Diplomacy Subject nations Barbarians
Script Events Decisions Missions