The population of the world is represented by individual "population units", or “pop” for short. Each population unit has a unique ID in the save game file.
A pop belongs to one of the four available social classes. It is the social class which determines what a pop produces!
- Citizens – generate research points and commerce income
- Freemen – generate manpower
- Tribesmen – generate manpower and tax income
- Slaves – generate tax income; additionally produce surplus goods
Population cannot be pro- or demoted by the player! Instead the population will slowly approach the "desired ratio" for the territory, which varries by the Nation, Buildings and Civilisation and other factors. This ratio and the rate of change can be affected by player choices, however.
There are a few effects that can directly change Social Class:
- When a City is occupied, there is a chance that Citizens will be demoted ⇒ Freemen and Freemen ⇒ Slaves.
- when any territory (including a city) is occupied), some of these generated slaves will be abducted (teleported) to a provincial or state capital of the sacking nation for no cost.
Each Citizen Pop at 100% Happiness produces per month:
- 0.25 Research Point
- 0.01 Commerce Value
- Base Happiness: 20%
Citizens only have a relevant desired Ratio in cities and metropolises. Their happiness is heavily affected by Civilisation level, and is otherwise rather hard to manage. Both their Ratio and happiness can be buffed via the Library Building. They are the only source of Research output (wich is buffed primarily by the Academy) and thus a must have even for Tribal Nations.
Each Freeman Pop at 100% Happiness produces per month:
- 10 Manpower
- Base Happiness: 25%
Freemen can be found in cities. Unless there are barracks, they are usually not found in Settlements. They are slightly easier to maintain then Citizens, but about equally affected by Civilisation Level. They produce relevant amounts of Manpower, so their usefullness is highly situational.
Each Tribesmen Pop at 100% Happiness produces per month:
- 0.015 Base Tax
- 5 Manpower
- Base Happiness: 100%
Tribesmen are very easy to keep happy, but receive a penalty for Civilisation level. Their values are relatively low - being beaten in income by the Citizens Commerce and Manpower by the Freemen - however actually getting those outputs is easier due to high base happiness.
In Tribal Governments, they make up 50% of the Settlement Population, limiting the space availible for slaves and thus tradegood and tax production. In cities they are less common, but still have a noticeable ratio.
For Non-Tribal nations they are generally of little use, besides as population that can be promoted or demoted to something more usefull. For these nations, they have a desired ratio of 0% everywhere.
Each Slave Pop at 100% Happiness produces per month:
- 0.019 Base Tax
- Base Happiness: 100%
- (semi-hidden) Extra Tradegoods
Slaves are the backbone of every economy during the timeframe of the game. There is not a single nation and a single territory that does not have, want or needs slaves. They are mostly found in settlements, where they make up 100% (Civilised) or 50% (Tribal) population. But they are equally found in cities. Their high base happiness can be missleading, as especially those captured in war tend to be of the wrong culture and religion.
While they produce more tax then any other Population type, their main purpose semm to be to produce additional Trade goods. Every 15 slaves (situational modifiers can lower that) the territory will produce an additional tradegood. For this, only the sheer number of slaves is relevant.
As mentioned, pops are the only source of Money, Research and Manpower! And there is a great many modifiers. For the human player to keep a better overview, there is the productivity-modifier, similar to Discipline for armies. It affects whatever the pop produces and is itself affected by various parameters throughout the game. Some of the modifiers to productivity are:
- #Happiness of pops
- Civilization level
E.g. the Centralization affects the productivity of Tribesmen.
Each pop has its own culture, religion and social class. The happiness value is applied to all pops sharing the same of the former three features living in a city.
Happiness of pops
Happiness impacts two attributes of the pop:
- Productivity: e.g. a freemen-type pop at 50% happiness generates only 5 Manpower instead of 10.
- Unrest: any pop with happiness less than 50% generates unrest to the city it currently resides in. A city with high enough unrest triggers a rebellion.
- City's civilization value
- Trade goods
- Religions and cultures different to the state's; such pops are also affected by assimilation and/or conversion (where applicable)
Population culture and religion
As each state has its own State Culture and Religion, so does each pop unit have its own as well. When a pop's religion and/or culture differs from the state in which they resides, that pop's happiness is affected (usually negatively). Ensuring that a majority of the state's pops are of the state's Culture and Religion is a crucial step in securing the stability and prosperity of the state.
Population of each social class can change through several means: Growth/Death and Conquest.
The base rate of population growth in each city in the game is 0.04%/month. When this number reaches 100% a new pop of that type is born in that city. There are many modifiers to this value. The population growth in a city is altered by factors such as terrain type, Stability, and availability of trade goods. Note that all bonuses are additive, therefore population growth omen power may multiple the growth rate in every city you have.
- Omen: Blessing of Love: National Population Growth: +0.1% + omen power modifiers
- Being in peace gives 0.04%/month.
- Above 50 stability gives progressively more growth rate. Having 100 stability gives 0.5%/month, while having 50 stability or lower gives 0%/month.
- Livestock presence in the province gives 0.1%/month, while every additional one gives 0.05%/month in the province's capital city.
- Fish presence in the province gives 0.1%/month, while every additional one gives 0.05%/month in the province's capital city.
- Several laws give various, but very low rate of growth, typically between 0.01%/month and 0.05%/month.
- As of Pompey patch, grain presence no longer boosts pop growth, but improves the population capacity.
If aiming to boost your population size, you can aim first for the omen power, stability (while it gives the highest potential growth rate, it is the most costly to keep high), and the two trade goods presence in the province. Having multiple of the trade goods, or other modifiers have an extremely low benefit, but might be worthwhile.
When a new pop starts to grow, its social class is determined by chance, from the available pops already living in the city. Its culture and religion is also determined upon it starting to grow. They are also randomly selected from the religion and culture already present in the city. For example, if there is no Tribesman in the city, it will never start to grow. Though, it is possible to promote all of your (for example) tribesman into freeman, and still end up with one, if it was already growing when you have promoted the already grown ones.
Population growth in a city can also become negative (by modifiers). If this happens, the growing pop will shrink instead. If there is no growing pop, an existing pop will be chosen (at random) and a progress bar toward 0 will start. If it reaches 0%, that pop will die.
Population is also gained through warfare. As cities are sacked, POWs are taken to the state capital or to the provincial capitals as slaves. It should be noted, that pops within the newly conquered city may be demoted:
- Citizen ⇒ Freemen (50% chance)
- Freemen ⇒ Slaves (50% chance)
Tribesmen and Slaves never change their social class upon conquest.
Population moves between cities under 4 circumstances:
- Conquest (enslavement)
- Scripted Events
- The player can move slaves by spending gold
- Tribal nations can move tribesman similar to slaves.
- Tribal nations can also trigger a "tribal migration" via the Government Interface
A slave pop can be moved from a city to any city in the same province, an adjacent city or a city across an adjacent sea-zone for a cost of 5 gold.
- Main article: Colonization
Populace is used to colonize new territories. At least 10 non-slave pops of the dominant culture are needed in any neighboring province.
Each territory has a base population capacity which is modified by a number of population capacity modifiers from terrain, technology, resources and events. These modifiers also apply on aqueducts and other things that may increase the base pop cap. Knowing which territories are good for population growth is essential in city placement and economic planning.
Some common modifiers include:
- Farmland: 50%
- Desert: -30%
- Mountains: -20%
- Jungle: -20%
- Forest: -10%
- Marsh: -10%
- Coastal: 10%
- Salt (in province): 10%
- Horses (surplus): 5%
- Warm climate: 50%
In every territory (city or settlement) one pop at time will be promoted and one at time will be demoted to reach the deisdered ratio of the population in that territory.
- Settllements: in monarchies and republics the base ratio is 100% slaves, in tribal nations is 50% tribesmen and 50% slaves. This can be modified building Barracks that increase the desidered ratio of freemen in settlements by +75%.
- Cities: the base ratio in monarchies is 35% citizens, 35% freemen, 0% tribesemen, 30% slaves; in republics is 34% citizens, 39% freemens, 0% tribesmen, 27% slaves; in tribal nations is 33% citizens, 33% freemen, 4% tribesmen, 30% slaves. This can be modified by laws and buildings (e.g. Libraries increase desidered ratio of citizen, Mills increase ratio of slaves).
The player can increase migration of non slaves pops from settlements to cities in order to promote more pops to citizen status, this is reccomended because citizens are the only source of research and are needed to keep up in technologies.
Every social class has a promotion speed value:
- Slave promoting: +4
- Tribesman promoting: +0.4
- Freeman promoting: +4
this can be directly modified building Academies (+0.5 each), using the Social mobility edict in the province (+5), enacting the second Land reform law in republics (+6).
To the values listed above are applied different modifiers. Some common modifiers include:
- Settlement: -25%
- Capital territory: 25%
- Province capital: 10%
- Coastal port: 10%
- Unrest: -1% every 0.1 unrest
- Number of Trade route: 5% every active trade route
- Road Network in territory: 2.5% for each road entering the territory
- Total population: 2.5% every pop living in the territory
- Positive centralization: 2.5% at 100 centralization
- Civic invention Granted Manumission at tech 10: 10%
- Civic invention Gradated Citizenship at tech 17: 20%