查看“人口”的源代码

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[[File:Population screen.png|right|600px|thumb|The main territory population interface|链接=Special:FilePath/Population_screen.png]]

The population of the world in ''Imperator Rome'' is represented by individual '''population units''', or '''pops''', each of whom live in a particular [[territory]] and owe their allegiance to the country that owns their home. Pops drive the economy and military of a nation and are the most important source of {{icon|cost}} gold (directly through {{icon|local tax}} taxes and indirectly through [[trade]], which produces {{icon|commerce value}} commerce), {{icon|manpower}} 人力, and {{icon|research points}} 研究点, but must also be kept {{icon|happiness}} happy and content lest they drive {{icon|unrest}} unrest in their province and [[rebellion|revolt]]. In general, pops cannot be interacted with directly and will {{icon|population growth}} grow, {{icon|assimilation}} assimilate, {{icon|conversion}} convert, {{icon|promotion}} promote, and {{icon|migration speed}} migrate of their own accord, but the use of [[governor policy|governor policies]] and the construction of [[infrastructure]] can be used to adjust the environment they live in and manipulate and control a country's demographics on a larger, more macro scale.

== 社会阶层 ==
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A pop belongs to one of the five available '''social classes''', or '''pop types'''. The social class of a pop is one of its most important properties and determines what a pop produces, its [[political weight]], what happiness modifiers it is affected by, and more.

# {{icon|nobles}} 贵族 - 产出 {{icon|research points}} 研究点数和 {{icon|trade routes}} 贸易路线
# {{icon|citizens}} 公民 – 产出 {{icon|research points}} 研究点数， {{icon|trade routes}} 贸易路线和 {{icon|manpower}} 人力
# {{icon|freemen}} 自由民 – 产出 {{icon|manpower}} 人力和 {{icon|local tax}} 税收
# {{icon|tribesmen}} 部落民 – 产出 {{icon|manpower}} 人力和 {{icon|local tax}} 税收
# {{icon|slaves}} 奴隶 – 产出 {{icon|local tax}} 税收和 {{icon|slaves for surplus}} 额外的贸易品

The class structure of a territory's population will approach its '''optimal ratio''' over time through pop {{icon|promotion}} promotion and {{icon|demotion}} demotion, the value of which is specific to each territory and varies by the territory's [[buildings]] and [[territory rank|rank]], the country's [[government]] form, local and national modifiers, and many other factors. This ratio and the rate of change can be affected by player choices, and promotion is additionally restricted by the pop's level of [[civic rights]] based on its culture.

There are also a few other effects that can directly change a pop's social class:
* When a territory is occupied, there is a chance that some pops will be immediately demoted one level: {{icon|nobles}} Nobles ⇒ {{icon|citizens}} Citizens (5% chance), {{icon|citizens}} Citizens ⇒ {{icon|freemen}} Freemen (25% chance), and {{icon|freemen}} Freemen ⇒ {{icon|slaves}} Slaves (25% chance). 
* When any territory is occupied, some of its pops will be enslaved according to the army's {{icon|enslavement efficiency}} enslavement efficiency and immediately moved to one of the occupier's territories, usually a provincial or country capital, as a new {{icon|slaves}} slave pop (keeping its culture and religion).
* Some events can also immediately promote or demote pops.

=== 贵族 ===
{{desc|Nobles|Nobles represent the elites in Rome, and nobility in monarchies. Typically, they would be owners of a [[wikipedia:Latifundium|Latifundium]].|image=Pop noble}}

Each Noble Pop at {{icon|happiness}} 100% Happiness produces per month:
* {{icon|research points}} {{green|+0.5}} 研究点
* {{icon|trade routes}} {{green|+0.15}} 贸易路线（不受幸福度影响）

贵族还具有以下特点:
* '''3.00''' [[political weight|Political Weight]]
* {{icon|food}} {{red|0.5}} 食物消耗
* {{icon|happiness}} '''-20%''' 基础幸福度
* {{icon|assimilation}} {{green|+0.40}} 基础同化
* {{icon|conversion}} {{green|+0.40}} 基础改信
* {{icon|demotion}} {{green|+2}} 基础降级速度
* {{icon|migration speed}} {{green|+0.4}} 基础移民速度

'''Nobles''' only have a relevant desired Ratio in cities, metropolises, and the capital (even if it does not have city status). Their happiness is heavily affected by {{icon|civilization}} civilisation level and is in general difficult but important to manage, with both the lowest 基础幸福度 and the highest political weight of all pop classes. Both their {{icon|noble ratio}} ratio and {{icon|noble happiness}} happiness can be increased via the {{icon|library}} library, while the {{icon|academy}} academy increases their {{icon|noble ratio}} ratio by half as much along with their (significant) {{icon|research points}} research output. 

Nobles are generally the most powerful and productive pop type and it can be advantageous to maximize the number of nobles in the country, as long as their happiness can be kept under control - their high {{icon|food}} 食物消耗 is significant, particularly in the {{icon|capital}} capital where they are concentrated in large numbers and will often outstrip the local food supply, and their low happiness and high political weight makes them dangerous if not properly appeased. [[Trade goods]] are an important source of happiness modifiers, and as they are applied-province wide it is usually best to focus most on noble ratio in cities in the capital province (which has the additional benefit of usually being primarily the primary culture).

Noble civic rights are rather exclusive, giving a combined {{icon|integrated culture happiness}} {{red|-4%}} Integrated Culture Happiness malus and {{icon|primary culture happiness}} {{red|-5%}} Primary Culture Happiness for every non-primary culture, which means that granting these rights give a heavy penalty and generally only primary culture pops will have the civic right and be able to promote to nobles. However, conquered noble pops will in general remain in significant numbers and non-integrated culture noble pops can be a significant source of {{icon|unrest}} unrest when conquering the cities and especially capital provinces of other countries, and will additionally be slow to assimilate, convert, and demote, ensuring that they can be a persistent problem.

=== 公民 ===
{{desc|Citizens|Citizens represent those with a [[wikipedia:Roman_citizenship|privileged legal status in Rome]].|image=Pop citizen}}

Each Citizen Pop at {{icon|happiness}} 100% Happiness produces per month:
* {{icon|research points}} {{green|+0.2}} 研究点
* {{icon|trade routes}} {{green|+0.03}} 贸易路线（不受幸福度影响）
* {{icon|manpower}} {{green|+2}} 人力（每年）

公民还具有以下特点:
* '''1.50''' [[political weight|Political Weight]]
* {{icon|food}} {{red|0.3}} 食物消耗
* {{icon|happiness}} '''-10%''' 基础幸福度
* {{icon|assimilation}} {{green|+0.60}} 基础同化
* {{icon|conversion}} {{green|+0.60}} 基础改信
* {{icon|promotion}} {{green|+6}} 基础升级速度
* {{icon|demotion}} {{green|+4}} 基础降级速度
* {{icon|migration speed}} {{green|+0.6}} 基础移民速度

'''Citizens''' generally only have a significant desired ratio in cities, metropolises, and the capital (even if it does not have city status), though most larger settlements will usually have room for one or two citizen pops as well. Both their {{icon|citizen ratio}} ratio and {{icon|citizen happiness}} happiness can be increased by the {{icon|court of law}} court of law. Citizen civic rights are associated with {{icon|integrated}} integrated cultures, and only integrated culture pops will be able to promote to citizens, which can prove to be an obstacle to gaining more citizens in cities with a high non-integrated culture population.

In general, citizens can be considered a weaker form of nobles - less production per pop, but easier to feed, please, and promote to, with a higher desired ratio and a less expensive [[civic rights|civic right]]. In most cities they will still make up a significant form of the population, and can be useful to focus on in cities dominated by {{icon|integrated}} integrated cultures that have not been given the full noble civic right.

=== 自由民 ===
{{desc|Freemen|Freemen represent the plebeians of Rome. Artisans and small holders.|image=Pop freemen}}

Each Freeman Pop at {{icon|happiness}} 100% Happiness produces per month:
* {{icon|local tax}} {{green|+0.005}} 税收
* {{icon|manpower}} {{green|+4}} 人力（每年）

自由民还具有以下特点:
* '''1.00''' [[political weight|Political Weight]]
* {{icon|food}} {{red|0.2}} 食物消耗
* {{icon|happiness}} '''0%''' 基础幸福度
* {{icon|assimilation}} {{green|+0.60}} 基础同化
* {{icon|conversion}} {{green|+0.60}} 基础改信
* {{icon|promotion}} {{green|+6}} 基础升级速度
* {{icon|demotion}} {{green|+6}} 基础降级速度
* {{icon|migration speed}} {{green|+1}} 基础移民速度

'''Freemen''' are found primarily in cities, but also have a significant base optimal ratio (20%) in the {{icon|settlement}} settlements of [[monarchy|monarchies]] and [[republic]]s. They are somewhat easier to maintain than citizens, but about equally affected by {{icon|civilization}} civilisation level. While freemen produce some {{icon|local tax}} tax their primary contribution is as main source of {{icon|manpower}} 人力, so their usefulness is highly situational depending on how much additional 人力 is needed (mostly medium-size countries that have enough pops to make a significant difference, while not being so large that additional 人力 is not really needed). Both their {{icon|freeman ratio}} ratio and {{icon|freeman happiness}} happiness can be increased via the {{icon|forum}} forum in {{icon|city}} cities and {{icon|metropolis}} metropolises, and {{icon|barracks}} barracks in {{icon|settlement}} settlements, and as the default [[civic rights|civic right]] in non-integrated cultures they will tend to be disproportionate represented in those areas.

=== 部落民 ===
{{desc|Tribesmen|These represent uncivilized folks, barbarians.|image=Pop tribesmen}}

Each Tribesmen Pop at {{icon|happiness}} 100% Happiness produces per month:
* {{icon|local tax}} {{green|+0.008}} 税收
* {{icon|manpower}} {{green|+3}} 人力

部落民还具有以下特点:
* '''0.75''' [[political weight|Political Weight]]
* {{icon|food}} {{red|0.1}} 食物消耗
* {{icon|happiness}} '''16%''' 基础幸福度
* {{icon|assimilation}} {{green|+0.40}} 基础同化
* {{icon|conversion}} {{green|+0.40}} 基础改信
* {{icon|promotion}} {{green|+4}} 基础升级速度
* {{icon|demotion}} {{green|+2}} 基础降级速度
* {{icon|migration speed}} {{green|+2}} 基础移民速度

'''Tribesmen''' have a relatively high 基础幸福度, but unlike all other pop classes receive a penalty for {{icon|civilization}} Civilisation level. Their production is comparable to {{icon|freemen}} freemen, with a focus on {{icon|manpower}} 人力 and some amount of {{icon|local tax}} tax income, though actually getting those outputs is generally easier with their higher 基础幸福度. In {{icon|settlement}} settlements, tribesmen {{icon|tribesman output}} output and {{icon|tribesman happiness}} happiness can be increased by building {{icon|tribal settlement}} Tribal Settlements.

For [[tribal]] nations, they make up 50% of the Settlement Population, limiting the space available for {{icon|slaves}} slaves and thus trade goods and tax production. In any cities, they are less common, but still have a noticeable ratio. Tribesmen will therefore usually make up a large proportion of a tribal country's population, increasing their {{icon|manpower}} 人力 relative to what would be expected from their population but usually with less income. Tribesmen also have a high base {{icon|migration speed}} migration speed which means that they will move around significantly more quickly than other pop types.

For non-tribal nations, while they are technically superior to {{icon|freemen}} freemen the significant happiness penalties from {{icon|civilization}} civilization value means that tribesmen are usually much better off be promoted or demoted to one of the other classes. For these nations, they have a desired ratio of 0% at any location unless a {{icon|tribal settlement}} Tribal Settlement is built, though their slow promotion/demotion speed means that tribesman-heavy territories will usually take some time to become properly useful.

=== 奴隶 ===
{{desc|Slaves|Slaves are mostly prisoners of war (POWs).|image=Pop slaves}}

每个奴隶人口每月产出：
* {{icon|local tax}} {{green|+0.015}} 税收

奴隶还具有以下特性：
* '''0.35''' [[political weight|Political Weight]]
* {{icon|happiness}} '''-30%''' 基础幸福度
* {{icon|food}} {{red|0.1}} 食物消耗
* {{icon|assimilation}} {{green|+0.60}} 基础同化
* {{icon|conversion}} {{green|+0.60}} 基础改信
* {{icon|promotion}} {{green|+10}} 基础升级速度
* {{icon|migration speed}} {{green|+0.05}} 基础移民速度

'''Slaves''' are the backbone of almost every economy during the time frame of the game and the primary source of income for many countries. There is no nation or territory that does not want, doesn't need or doesn't have slaves. They are mostly found in {{icon|settlement}} settlements, where they have a base optimal ratio of 80% ([[monarchy]]/[[republic]]) or 50% ([[tribal]]) of the population, but are also found in significant proportions in cities. Their {{icon|slave happiness}} happiness, {{icon|slave output}} output and {{icon|slave ratio}} desired ratio can all be increased by the {{icon|mill}} mill in territories with city status, and {{icon|slave output}} output by the {{icon|slave estate}} slave estate in {{icon|settlement}} settlements. While slaves can appear through demotion and population growth like all other pop types, slaves can also uniquely be acquired through {{icon|enslavement efficiency}} the enslavement of pops when occupying enemy territories, as well as through {{icon|slave raid}} slave raiding for countries with the relevant [[military traditions]]. For many war-focused countries, enslavement can be the primary source of population growth in a nation's core territories, with slaves eventually assimilating/converting and promoting up to swell the ranks of the upper classes as well.

In addition to producing more {{icon|local tax}} tax income than any other pop type, slaves can also uniquely produce additional [[trade goods]] in a territory, based on the {{icon|slaves for surplus}} slaves needed for local surplus value of the territory. This value is a base of 15 in {{icon|settlement}} settlements and 20 in {{icon|city}} cities and {{icon|metropolis}} metropolises, which can be lowered by the {{icon|mine}} mine and {{icon|farming settlement}} farming settlement buildings in {{icon|settlement}} (as well as a large variety of other modifiers), and gives 1 extra trade good for every multiple (rounded down) of the {{icon|slaves for surplus}} slaves needed for local surplus in slaves there are in that territory.

Their happiness can be difficult to keep high, as those captured in war tend to be of the wrong [[culture]] and [[religion]]. Importantly, however, the output of slaves does not depend on their happiness, which means that the primary concern of slave happiness is controlling the {{icon|unrest}} unrest they produce, which given their low political weight is typically not too high.

== 产出 ==
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Depending on their class, pops produce various different types of resources, including {{icon|wealth}} gold, {{icon|manpower}} 人力, and {{icon|research points}} 研究点, and are the often main (or only) source of these resources in the game. In addition to the output modifiers for each specific resource, the {{icon|local output modifier}} '''population output''' modifier will also increase the production of all resources produced by pops, and is in general one of the most powerful economic modifiers in the game. Pop output modifiers combine additively with resource-specific modifiers, but are combined multiplicatively with the output modifier from {{icon|happiness}} happiness (for classes where happiness is relevant to production). This gives the following formula for the output of each individual resource produced by a pop:
: <math>\text{Pop Output for Resource}= \text{Base Pop Output for Resource} \cdot \frac{100% + \text{Pop Output Modifier} + \text{Resource Output Modifier}}{100%} \cdot \frac{\text{Pop Happiness}}{100%}</math>

Note that unlike with all other resources, output modifiers do '''not''' affect the number of {{icon|trade routes}} trade routes produced by a pop, which is always constant for each pop (depending on its class).

Some of the more important sources of {{icon|local output modifier}} population output modifiers include:
{{MultiColumn|
* {{red|-30%}} base value
* {{red|-15%}} in {{icon|settlement}} settlements
* {{green|+5%}} in the {{icon|capital}} capital territory
* {{green|+10%}} in {{icon|province capital}} province capitals
* {{green|+1%}} each point of {{icon|civ}} civilization value
* {{red|-30%}} if the {{icon|culture}} dominant culture in the territory is not an {{icon|integrated}} integrated culture
* {{red|-20%}} in occupied territories
* {{green|+1%}} for each {{icon|horses}} Horses [[trade goods|trade good]] in the province
* {{green|+1%}} for each {{icon|steppe horses}} Steppe Horses [[trade goods|trade good]] in the province
* {{green|+3%}} for each {{icon|elephants}} Elephants [[trade goods|trade good]] in the province
* {{red|-4%}} per governor {{icon|finesse}} finesse plus a base of {{red|-4%}} with the [[File:Harsh_treatment.png|28px]] Harsh Treatment [[governor policy]]
* {{red|-4%}} per governor {{icon|finesse}} finesse plus a base of {{red|-4%}} with the [[File:Policy_local_autonomy.png|28px]] Local Autonomy [[governor policy]]
* {{green|+5%}} in the {{icon|capital}} capital province
* {{green|+1.5%}} per governor {{icon|finesse}} finesse
|2}}

Pop output can also be affected on a class-specific basis with the {{icon|noble output}} '''noble output''', {{icon|citizen output}} '''citizen output''', {{icon|freeman output}} '''freeman output''', {{icon|tribesman output}} '''tribesman output''', and {{icon|slave output}} '''slave output''' modifiers. Like with happiness modifiers, each of these modifiers has three different variants that determine wits scope - '''local''', which only affects pops of that class in a particular territory; '''culture''', which affects all pops of that class with a specific {{icon|culture}} culture, or '''national''', which affects all pops of a certain class in an entire country. These modifiers are in general much more common than the general pop output modifier and can come from a large variety of sources, such as [[buildings]], [[trade goods]], [[deity|deities]] and [[omen]]s, [[laws]] and [[government]] forms, [[inventions]], governor [[traits]], and more.

== 幸福度 ==
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[[File:Pop happiness - Hellenic Roman Citizen .jpg|thumb|right|600px|You can find the happiness of each pop by going to the Province tab, and then hovering on the icon of one of the pops available|链接=Special:FilePath/Pop_happiness_-_Hellenic_Roman_Citizen_.jpg]]
{{icon|happiness}} '''Happiness''' represents how content and satisfied a particular pop is with the current government, affecting both how much of its production actually gets collected by the state as well as how willing the pop is to support resistance - or even rebellion - against the current government. Each of the five [[#Social classes|pop types]] has a certain '''基础幸福度 value''', varying from -30% for {{icon|slaves}} slaves to 16% for {{icon|tribesmen}} tribesmen. Then, there are a large number of local and national happiness modifiers that are applied, including but not limited to:
* {{icon|culture}} [[Culture]]
* {{icon|religion}} [[Religion]]
* {{icon|civilization}} [[City#Civilization_value|Civilization value]]
* [[Trade goods]]
* {{icon|law}} [[Laws]]
* {{icon|invention}} [[Inventions]]
* {{icon|stability}} [[Stability]]
* [[Buildings]]
* [[National ideas|Ideas]]

In general, there are 4 different sets of modifiers that will each affect a different set of pops:
* General happiness modifiers ({{icon|happiness}} '''(Local) Population Happiness''')
* Pop class modifiers ({{icon|noble happiness}} '''Noble Happiness''', {{icon|citizen happiness}} '''Citizen Happiness''', {{icon|freeman happiness}} '''Freeman Happiness''', {{icon|tribesman happiness}} '''Tribesman Happiness''', and {{icon|slave happiness}} '''Slave Happiness''' modifiers)
** Each of these modifiers has three variants: '''Local Happiness''', applied to a single territory or province; '''Culture Happiness''', applied to pops of a particular culture; and '''National Happiness''', applied to all pops of the specific class across the whole country
* Culture modifiers ({{icon|happiness}} '''Culture Happiness''', {{icon|integrated culture happiness}} '''Integrated Culture Happiness''', {{icon|wrong culture happiness}} '''Unintegrated Culture Happiness''', and {{icon|wrong culture group happiness}} '''Unintegrated Culture Group Happiness''' modifiers) 
* Religion modifiers ({{icon|state religion happiness}} '''State Religion Happiness''' and {{icon|pantheon}} state religion pantheon deity modifiers)

A pop's happiness is the sum of all happiness modifiers it is affected by over its 基础幸福度 value, and has a range of '''0%''' to '''100%''', with 50% the median value at which they are neither content nor discontent. The average happiness of all pops of a particular class is displayed in the territory view.

Happiness has two main effects on a pop:
* {{icon|local output modifier}} Output: a pop's output (except for {{icon|slaves}} slaves) is scaled according its current happiness, before other modifiers are applied. For instance, a freeman pop at 50% happiness generates a base of only {{icon|manpower}} 2 人力 instead of 4.
* {{icon|unrest}} Unrest: any pop with happiness less than '''50%''' will generate unrest in the territory it currently resides in, scaled by its happiness and '''political weight''', which acts as a multiplier on how much unrest it produces - for instance, an angry {{icon|nobles}} noble pop will produce far more unrest than a discontent {{icon|slaves}} slave. High unrest will lower {{icon|province loyalty}} province loyalty and may eventually lead to [[rebellion]]s.

The unrest produced by each unhappy pop is scaled to the total population of the territory, the pop's political weight, and how much its happiness is below 50%, giving a formula of approximately:
: <math>\text{Unrest}=10 \cdot \frac{1}{\text{Territory Population}} \cdot \text{Pop Political Weight} \cdot \frac{50 - \text{Pop Happiness}}{50}</math>

The total unrest for each territory is simply the sum of the unrest produced over all its pops.

=== Strategy ===
As with all modifiers, national modifiers are almost always better than local modifiers, even if the value is somewhat weaker. Even relatively small changes in happiness can have a noticeable impact on pop output or unrest generated if applied across a large enough number of pops.

Generally, the largest differences in overall population happiness are between integrated cultures and unintegrated, especially unintegrated culture group, pops, with different strategies relevant in each area. While there can be significant differences in pop class happiness, these are usually not too relevant as, for instance, {{icon|slaves}} slaves do not have an output difference from happiness and have a political weight too low to be particularly relevant, while for many countries {{icon|tribesmen}} tribesmen will only exist in appreciable quantities in recently conquered areas where low happiness is to be expected in the first place.

In core, primary/integrated culture and state religion areas, happiness will rarely be low enough to produce any significant unrest and the primary concern of happiness is instead to maximize pop output, as these are often the most populated and productive parts of a country. Since {{icon|slaves}} slaves do not change their output based on happiness, the primary focus in core areas is to maximize the happiness of the highly productive {{icon|nobles}} nobles and then {{icon|citizens}} citizens, typically by building their associated buildings in {{icon|city}} cities, importing their specific trade goods (generally only available in significant quantities a little bit into the game), and increasing {{icon|civilization}} civilization level (though only as a general, long term goal). Focusing on {{icon|freemen}} freemen happiness may also be situationally useful, but by the time a country is wealthy enough to invest in {{icon|freemen}} freemen it usually no longer has a pressing need for more 人力, at least as opposed to {{icon|research points}} research and {{icon|commerce}} commerce income (from trade routes). Note that happiness is capped at 100%, which can often be exceeded by the accumulation of various bonuses by the midgame, and while it can be useful to have some buffer in case {{icon|stability}} stability drops or {{icon|war exhaustion}} war exhaustion increases at some point increasing happiness ceases to be useful and it can be better to invest building or trade route slots into other areas.

In contrast, recently conquered provinces of an unintegrated culture (especially of a different culture group) and different religion will be particularly difficult to please, and in general unless the country has a large number of {{icon|wrong culture group happiness}} unintegrated culture group happiness bonuses they will be virtually impossible to satisfy completely. For these areas, trying to fully manage happiness is very costly and it is easiest to just appoint a loyal, uncorrupt governor and build enough {{icon|fort}} forts in the province to keep {{icon|unrest}} unrest and {{icon|province loyalty}} province loyalty under control in the short to medium term; if not even this is enough, the easiest way to quickly reduce the penalties from unhappiness is to try to appease any nobles and/or citizens in the province (who are normally the most unhappy as well as the largest generators of unrest), typically by building their happiness-improving buildings in the cities and/or importing the specific [[trade goods]] that improve their happiness. If {{icon|stability}} stability is low, focusing on raising that can also help significantly with happiness problems. Over time pops will convert/assimilate and become happier, decreasing the proportion of discontent pops to the point where the forts may no longer be needed - building a {{icon|theater}} grand theater and {{icon|temple}} great temple in the main cities of the province can speed this up process significantly.

== 同化 ==
{{main|Assimilation}}
{{#lst:Assimilation|assimilation_body}}

== 改信 ==
{{main|Conversion}}
{{#lst:Conversion|conversion_body}}

== 人口改变==
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=== 人口增长 ===
{{icon|local population growth}} The main way that new pops appear in the game is through natural '''population growth'''. Every colonizable territory in the game will have one randomly chosen pop growing at a time, gaining progress each month according to the territory's '''Population Growth Speed''', determined by the sum of all {{icon|population growth}} '''local''' and '''national population growth''' modifiers. Once the population growth progress reaches '''100%''', a new pop will be created in the territory with the same pop class, culture, and religion of the pop it originally grew from. Note that a pop will continue to grow even if the pop it is growing from its killed, moved away, changed in any way, which might result in a newly grown pop no longer sharing the same characteristics of the original pop once it finishes if the original pop changed in the meantime.

Important sources of population growth are listed below:
* {{green|+0.01%}} base value for all territories
* {{green|+0.003%}} per point of {{icon|civilization}} civilization value
* {{red|-0.03%}} for each {{icon|population}} pop over the {{icon|population capacity}} population capacity
* {{green|+0.02%}} for every 12 months of {{icon|food}} the province's total 食物消耗 that the province has stored, up to a maximum of 120 Months
* {{red|-0.06%}} for [[blockade]]d territories
* {{red|-0.01%}} for looted territories
* {{red|-0.20%}} for raided territories
* {{red|-0.25%}} for pillaged territories
* {{green|+0.5%}} for depopulated territories
* {{green|+0.03%}} when at peace
* {{green|+0.01%}} for every point of {{icon|stability}} stability over '''50'''
* {{green|+0.025%}} for each tier of a {{icon|wonder}} great wonder's [[File:Gw effect expanding population.png|28px]] Fertile Nation effect
* {{green|+0.01%}} with the {{icon|invention}} Grain Rations ({{icon|rel}} Religious Advances 1), {{green|+0.02%}} with {{icon|invention}} Obstetrics ({{icon|rel}} Religious Advances 10), and {{green|+0.02%}} with {{icon|invention}} Encouragement of Migration ({{icon|rel}} Religious Advances 14)
* {{green|+0.10%}} as a passive modifier of many [[deity|deities]] ({{green|+0.125%}} if the {{icon|holy site}} holy site is held)
* {{green|+0.08%}} per {{icon|omen power}} 100% omen power for many {{icon|omen power}} omens ({{green|+0.10%}} per {{icon|omen power}} 100% omen power if the {{icon|holy site}} holy site is held)
* {{green|+0.05%}} with the {{icon|law}} Infrastructure Policy [[Monarchy]] law
* {{green|+0.03%}} with {{flag|Epidauros|0}} Epidauran Heritage ([[Epidauros]]), {{flag|Halikarnassos|0}} Halicarnassan Heritage ([[Halikarnassos]]), {{flag|Metapontum|0}} Metapontine Heritage ([[Metapontum]]), {{flag|Kios|0}} Ciusan Heritage ([[Kios]])
* {{red|-0.01%}} with Euboean Heritage (cultural)
* {{green|+0.02%}} from [[governor]]s with {{icon|gluttonous}} Gluttonous trait
* {{red|-0.02%}} from [[governor]]s with {{icon|self-controlled}} Self-controlled trait

If aiming to boost population growth, {{icon|stability}} stability (while it gives the highest potential growth rate, it is the most costly to keep high) and {{icon|food}} stored food are generally the most effective. The other modifiers are smaller and generally have a higher opportunity cost. There are also a large number of other modifiers from [[events]], [[decisions]], and [[missions]] that can increase or decrease population growth in a territory, most notably the [[Roman Warm Period events|Roman Warm Period]].

If the population growth speed is negative - usually as a result of starvation, or sometimes significant overpopulation - pops in the territory will instead begin to '''die'''. Any pop that is growing will instead begin to lose progress, and if it reaches 0 a randomly pop will be chosen to begin dying. The progress bar will be reset to 100% and gradually lose progress according to the current population growth speed, and once the growth progress reaches 0 the pop will be killed and another pop will begin to die.

Note that population growth in general does not scale according to the actual population of the territory, but instead remains constant as the population grows (within the {{icon|pop cap}} population capacity). This means that population growth tends to be linear over the course of the game, not exponential, and that population growth generally scales best to the {{icon|territories}} number of owned territories rather than the {{icon|population}} population of a country.

=== 占领 ===
{{main|Enslavement}}
When a territory is occupied an by army led by a {{icon|commander}} commander, a certain proportion of the population (approximately the population of the territory multiplied by the occupying army's {{icon|enslavement efficiency}} enslavement efficiency) will be captured, with around '''1/3''' killed directly (and the rest enslaved and sent back to the occupying army's homeland). In a large scale war, this can result in significant demographic losses if a country's population centres are successfully sieged down. When a {{icon|city}} city, {{icon|metropolis}} metropolis, or {{icon|capital}} is occupied, the commander of the army will also get an event to decide how much to sack the city, which can result in further loss of population if the commander decides to let the army loose.

== 人口移动 ==
{{SVersion|2.0}}
While every pop lives in a certain territory, they are generally not directly bound to their current home and under various circumstances may decide to move, or be forcibly moved, to another territory. In addition to [[events]], [[decisions]], [[missions]], and certain interactions, there are a number of mechanics by which pops can move from territory to territory, some happening passively with others depending more strongly on the country's actions.

=== 移民 ===
{{icon|migration speed}} Free pops will '''migrate''' of their own volition to nearby territories in pursuit of economic opportunities, or to escape deteriorating circumstances in their current home. A territory's general attractiveness is represented by its {{icon|migration attraction}} '''migration attraction''', which is determined largely by available {{icon|population capacity}} population capacity and {{icon|civilization}} civilization value, but can also be decreased - sometimes significantly so - by disruptive actions and events such as {{icon|unrest}} unrest, {{icon|siege}} sieges and occupation, [[File:Food_deficiency.png|28px]] [[Food#Province_food|starvation]], and overpopulation. Certain [[governor policy|governor policies]] can also be used to some extent to adjust migration attraction.

Important modifiers to {{icon|migration attraction}} migration attraction include:
{{MultiColumn|
* {{green|+1}} base value for all territories
* {{red|-3}} for {{icon|settlement}} settlements
* {{green|+2}} for {{icon|metropolis}} metropolises
* {{green|+0.15}} for each free slot of {{icon|population capacity}} population capacity
* {{green|+0.05}} per point of {{icon|civilization}} civilization value
* {{green|+2}} for the {{icon|capital}} capital
* {{green|+1}} if the territory is a {{icon|province capital}} province capital
* {{green|+5}} if the territory has a {{icon|holy site}} holy site
* {{green|+0.05}} for each outgoing {{icon|road}} road in a territory
* {{green|+1}} for territories adjacent to a {{icon|river}} major river
* {{green|+0.1}} per {{icon|port building}} port
* {{red|-1}} for each point of {{icon|unrest}} unrest
* {{red|-10}} if the territory is [[File:Food_deficiency.png|28px]] [[Food#Province_food|starving]]
* {{red|-4}} for each {{icon|population}} pop over the {{icon|population capacity}} population capacity
* {{red|-10}} if the territory is occupied
* {{red|-30}} if the territory is under {{icon|siege}} siege
* {{red|-2}} if the territory was recently looted
* {{green|+5}} if the territory was depopulated
* {{red|-0.6}} per governor {{icon|finesse}} finesse plus a base of {{red|-6}} with the [[File:Harsh_treatment.png|28px]] Harsh Treatment [[governor policy]]
* {{green|+0.1}} per governor {{icon|finesse}} finesse plus a base of {{green|+1}} in the {{icon|province capital}} province capital with the [[File:Centralize_pop.png|28px]] Centralize Population [[governor policy]]
* {{red|-0.5}} per governor {{icon|finesse}} finesse plus a base of {{red|5}} in non-{{icon|province capital}} province capital territories with the [[File:Centralize_pop.png|28px]] Centralize Population [[governor policy]]
* {{red|-0.5}} per governor {{icon|finesse}} finesse plus a base of {{red|5}} in the {{icon|province capital}} province capital with the [[File:Decentralize_pop.png|28px]] Decentralize Population [[governor policy]]
* {{green|+0.1}} per governor {{icon|finesse}} finesse plus a base of {{green|+1}} in non-{{icon|province capital}} province capital territories with the [[File:Decentralize_pop.png|28px]] Decentralize Population [[governor policy]]
|3}}

All pops other than {{icon|slaves}} slaves are eligible to migrate as long as they are not currently busy ({{icon|assimilation}} assimilating, {{icon|conversion}} converting, {{icon|promotion}} promoting, or {{icon|demotion}} demoting). Every territory can then have '''1''' pop that is migrating away (chosen at random) to another territory with higher {{icon|migration attraction}} migration attraction, with pops generally preferring targets with higher attraction. There is no limit, however, to the number of pops that can be immigrating to a territory at a given time, which generally results in territories with high {{icon|migration attraction}} migration attraction receiving a disproportionate share of migrants. Pops can migrate between neighbouring territories (including those with a different owner, though not to or from uncolonized territories), territories in the same [[province]], or between any two territories in the same country that both have a {{icon|port}} port.

As with all passively occurring pop activities, when a pop is emigrating it will gain a certain amount of progress each month, determined by the combined {{icon|migration speed}} '''migration speed''' modifiers of the pop, territory (that the pop is emigrating from), and the country, with the pop moving to its new home once the progress bar reaches 100%. Each pop class has a certain 基础移民速度, with {{icon|tribesmen}} tribesmen the fastest and {{icon|nobles}} nobles and {{icon|citizens}} citizens the slowest, while migrating from {{icon|settlement}} settlements is also much slower than from {{icon|city}} cities and {{icon|metropolis}} metropolises. Geographical considerations such as being adjacent to a {{icon|river}} river, being on the {{icon|coast}} coast, and especially having a {{icon|port}} port will increase migration speed, as do factors disrupting life in the territory of origin such as {{icon|unrest}} unrest, overpopulation, and starvation. Migration speed can be further increased by certain {{icon|law}} laws, {{icon|invention}} inventions, and [[governor policy|governor policies]], as well.

Important modifiers to {{icon|migration speed}} migration speed include:
{{MultiColumn|
* {{green|+0.4}} for {{icon|nobles}} nobles
* {{green|+0.6}} for {{icon|citizens}} citizens
* {{green|+1}} for {{icon|freemen}} freemen
* {{green|+2}} for {{icon|tribesmen}} tribesmen
* {{green|+0.05}} for {{icon|slaves}} slaves
* {{green|+10%}} for each outgoing {{icon|road}} road
* {{red|-75%}} for {{icon|settlement}} settlements
* {{green|+10%}} for territories with a {{icon|river}} nearby river
* {{green|+25%}} for territories adjacent to a {{icon|river}} major river
* {{green|+0.25}} if the territory is {{icon|coast}} coastal
* {{red|-25%}} for normal winters
* {{red|-50%}} for severe winters
* {{green|+0.1}} per {{icon|port building}} port
* {{red|-25%}} from a {{icon|barracks}} Barracks
* {{red|-25%}} from a {{icon|slave estate}} Slave Estate
* {{red|-25%}} from a {{icon|mine}} Mine
* {{red|-25%}} from a {{icon|farming settlement}} Farming Settlement
* {{green|+75%}} from a {{icon|provincial legation}} Provincial Legation
* {{green|+25%}} for each point of {{icon|unrest}} unrest
* {{green|+10}} if the territory is [[File:Food_deficiency.png|28px]] [[Food#Province_food|starving]]
* {{green|+3}} for each {{icon|population}} pop over the {{icon|population capacity}} population capacity
* {{green|+2.5%}} for each owned territory with a {{icon|port}} port in the province
* {{green|+0.1}} per governor {{icon|finesse}} finesse plus a base of {{green|+1}} with the [[File:Harsh_treatment.png|28px]] Harsh Treatment [[governor policy]]
* {{green|+0.2}} per governor {{icon|finesse}} finesse plus a base of {{green|+2}} with the [[File:Centralize_pop.png|28px]] Centralize Population [[governor policy]]
* {{green|+0.2}} per governor {{icon|finesse}} finesse plus a base of {{green|+2}} with the [[File:Decentralize_pop.png|28px]] Decentralize Population [[governor policy]]
* {{green|+10%}} with the {{icon|invention}} Coloniae {{icon|civ}} Civic invention
* {{green|+20%}} with the {{icon|invention}} Land Tithe {{icon|civ}} Civic invention
* {{green|+0.05%}} for each point of ruler {{icon|corruption}} corruption
* {{green|+1.5}} with the {{icon|law}} Military Settlement Policy [[Republic]] law
* {{green|+1.5}} with the {{icon|law}} Lex Servilia Glaucia {{flag|Rome|0}} [[Rome|Roman]] [[Republic]] law
* {{green|+10%}} if on the defending side in a {{icon|war}} war
* {{green|+5%}} with {{flag|Nabatea|0}} Nabatean Heritage ([[Nabatea]])
|3}}

While seemingly quite slow, migration can be a powerful force over the course of the game, and generally gives a substantial contribution to the population growth of cities. Migration between {{icon|port}} port provinces is particularly powerful given the much larger pool of territories that immigrants can be drawn from, which makes it particularly useful to place the {{icon|capital}} capital and/or other major economic centres at ports beyond the base bonuses that they give. On a smaller scale, immigration from settlements in the countryside to the local provincial capital or other nearby cities also contributes to urbanization over the course of the game, at least in settled nations; while the predominant {{icon|slaves}} slave population in territories cannot migrate, the local {{icon|freemen}} freemen can, which reduces the ratio of freemen in the settlement and, unless disabled, allows the remaining {{icon|slaves}} slaves to promote into their place, allowing for further migration.

=== 手动移动 ===
While {{icon|slaves}} slaves cannot migrate on their own, they can still be '''moved manually''' by their owner country through the territory population interface to any owned territory that either neighbours or is in the same [[province]] as the territory of origin. [[Tribal]] nations can additionally manually move owned {{icon|tribesmen}} tribesmen pops through the same mechanic as well. Unlike migration, manual movement of pops happens instantaneously with no cooldowns or other restrictions - if desired, a single pop can be moved multiple times between many different territories on the same day - though there is also a base cost of {{icon|wealth}} {{red|5}} gold every time a pop is moved, which for {{icon|slaves}} slaves can be modified by the {{icon|slave move cost}} '''move slaves cost''' modifier, available only as a {{green|-25%}} reduction with the {{icon|vegetables}} vegetables capital bonus.

Since the number of [[trade goods]] a territory produces is (partly) tied to the number of slaves it has, moving {{icon|slaves}} slaves can to some extent can be used to control and manage the country's production of [[trade goods]], such as by moving slaves to territories that produce more expensive/desirable trade goods or more careful optimization to push a territory's {{icon|slaves}} slave population just over the next threshold for producing another instance of the trade good sooner than population growth would have occurred naturally. Using rural {{icon|slaves}} slaves to increase the population of nearby {{icon|city}} cities can also be useful to speed up urbanization, as most of the slaves will eventually promote and begin producing other resources such as {{icon|manpower}} 人力, {{icon|research points}} 研究点, and {{icon|trade routes}} trade routes that may be more useful. Note that moving the last pop away from a territory will decolonize the territory and make it unowned.

In addition, manually moving pops is particularly useful for quickly shifting the demographics of a territory to have a dominant {{icon|culture}} integrated culture and {{icon|religion}} state religion to meet the requirements for [[colonization]] more quickly than {{icon|assimilation}} assimilation and {{icon|conversion}} conversion would normally allow. Note that with sufficient gold, a {{icon|slaves}} slave pop (or a {{icon|tribesmen}} tribesmen pop, for [[tribal]] countries) can be moved an arbitrarily large distance between connected territories by moving the pop to the edge of the [[province]], using the adjacency condition to move the pop into an adjacent territory in the next province, and continuing until the pop has been moved to its desired location. This means that even territories far away from a significant source of {{icon|culture}} integrated culture and {{icon|religion}} state religion pops can have pops moved there to begin colonization, if the country is willing to spend enough {{icon|wealth}} gold.

=== 奴役 ===
{{main|Enslavement}}
当一支由{{icon|commander}} 指挥官领导的军队占领敌国领土时，该领土的一部分人口可能会被 {{icon|enslavement}} '''奴役'''。被强制降级为 {{icon|slaves}}奴隶身份（但保留其文化和宗教），作为战争战利品被送回本国。被俘虏的人口数量是根据占领军的 {{icon|enslavement efficiency}}'''奴役效率（enslavement efficiency）'''与领土人口的百分比而定，其中大约有'''2/3'''的人口会被真正奴役并送回本国（另外1/3的被俘虏人口则被杀害）。被奴役的人口通常会根据领土的 {{icon|migration attraction}} 移民吸引力进行分配，更倾向于 {{icon|capital}} 首都领土（以及次要程度的省会），同时会避开任何已达到或超过 {{icon|population capacity}} 人口容量的领土。

除了直接征服，奴役是增加一个国家人口的最有效方式之一，如果存在易于占领的领土，通常最好占领敌国中对你不重要的领土，以最大化奴役人口的数量。奴役人口在城市中的集中意味着它们通常最终会晋升，壮大高阶阶层的队伍。

洗劫大城市和人口稠密地区可以成为祖国的经济和人口的巨大助益，但对于那些人口被掠夺的地区来说，情况恰恰相反，即使是人口最多的地区，如果它们不断遭受争夺、占领和洗劫，最终也会被严重甚至完全地人口流失并毁坏，这使得领地被敌方占领充满危险，即使实际上敌方没有对该国施加任何要求。

=== 殖民 ===
{{main|Colonization}}
当附近的未被占有的领土被殖民时，将会有一个整合文化和国教的人口从殖民源地移动到被殖民的领土，而且这一移动是免费的。

== 人口容量 ==
{{SVersion|2.0}}
{{icon|pop cap}} Each territory has a certain '''population capacity''', which determines how large of a {{icon|population}} population a territory's terrain and infrastructure can support. Territories have a base {{icon|pop cap}} population capacity of '''10''', which is modified by a number of modifiers from terrain, technology, buildings, events, and more. Knowing which territories are good for population growth is essential in city placement and economic planning; it is almost always better to construct new {{icon|city}} cities in territories with a higher base population capacity, as larger cities are almost always richer and more productive than smaller ones, and {{icon|pop cap}} population capacity is usually the main factor that restricts the growth of cities. Note that {{icon|pop cap}} population capacity is a different value and modifier, though related, from {{icon|food}} food, which also services as a limitation to the population of a territory.

一些最重要的{{icon|pop cap}} '''人口容量''' modifier 包括：
{{MultiColumn|
* {{green|+5}} for {{icon|settlement}} settlements
* {{green|+22}} for {{icon|city}} cities
* {{green|+30}} and {{green|+10%}} for {{icon|metropolis}} metropolises
* {{green|+0.25%}} per point of {{icon|civilization}} civilization value
* {{green|+10%}} for {{icon|farmland}} farmland terrain
* {{red|-10%}} for {{icon|forest}} forest terrain
* {{red|-10%}} for {{icon|marsh}} marsh terrain
* {{red|-15%}} for {{icon|jungle}} jungle terrain
* {{red|-20%}} for {{icon|mountain}} mountains terrain
* {{red|-25%}} for {{icon|desert}} desert terrain
* {{green|+5%}} if there is a {{icon|river}} nearby river
* {{green|+10%}} if adjacent to a {{icon|river}} major river
* {{green|+5%}} for {{icon|coast}} coastal territories
* {{green|+5%}} for territories with a Warm [[Climate]]
* {{red|-15%}} for territories with a Arid [[Climate]]
* {{red|-20%}} for territories with a Frigid [[Climate]]
* {{red|-25%}} for territories with a Alpine [[Climate]]
* {{green|+10}} in the {{icon|capital}} capital territory
* {{green|+6}} in {{icon|province capital}} province capitals
* {{green|+10%}} from {{icon|tribal settlement}} tribal settlements
* {{green|+1}} per {{icon|port building}} port
* {{green|+4}} from {{icon|aqueduct}} aqueducts
* {{red|-10%}} from {{icon|earthworks}} earthworks
* {{green|+5%}} from a {{icon|wonder}} [[great wonder]] with a tier I [[File:Gw effect expanding population.png|28px]] Fertile Nation effect
* {{green|+7.5%}} from a {{icon|wonder}} [[great wonder]] with tier II [[File:Gw effect expanding population.png|28px]] Fertile Nation effect
* {{green|+10%}} from a {{icon|wonder}} [[great wonder]] with tier III [[File:Gw effect expanding population.png|28px]] Fertile Nation effect
* {{green|+15%}} from a {{icon|wonder}} [[great wonder]] with tier IV [[File:Gw effect expanding population.png|28px]] Fertile Nation effect
* {{green|+2.5%}} from each {{icon|civic investment}} State Infrastructure [[province investment]]
* {{green|+25%}} from the [[File:Idea city plan.png|28px]] City Planning [[national idea]]
* {{green|+1%}} from each level of {{icon|civ}} [[Advance|Civic Advances]]
* {{green|+5%}} from the {{icon|invention}} Urban Planning {{icon|civ}} Civic invention
* {{green|+5%}} from the {{icon|invention}} Census Data {{icon|ora}} Oratory invention
* {{green|+5%}} from the {{icon|invention}} Imperial Calendar {{flag|Seleukid Empire|0}} Seleukid {{icon|ora}} Oratory invention
* {{green|+5%}} from the {{icon|invention}} Cataract Surgery Indian {{icon|ora}} Oratory invention
* {{green|+10%}} from the {{icon|invention}} Pedagoguery {{icon|civ}} Civic invention
* {{red|-10%}} for {{icon|government}} [[tribal]] countries
* {{green|+10%}} as a passive modifier of many [[deity|deities]] ({{green|+12.5%}} if the {{icon|holy site}} holy site is held)
* {{green|+5%}} from {{flag|Maurya|0}} Heritage of Chandragupta ([[Maurya]])
* {{green|+10%}} from River Plains group [[heritage]]
|3}}

In addition, there is also the distinct {{icon|pop cap}} '''Total Population Capacity''' modifier, which is applied multiplicatively after all the normal population capacity modifiers have been applied to get the territory's final population capacity. The only source of this is a  {{red|-75%}} modifier if the territory's province has run out of {{icon|food}} food and has a Critical Food Supply.

It is theoretically possible to raise the population capacity of any territory as high as desired by stacking bonuses from the {{icon|civic investment}} State Infrastructure [[province investment]] and {{icon|civ}} [[Advance|Civic Advances]], but the small percentage increases means that this is prohibitively expensive. However, as in {{icon|city}} cities and metropolises every 10 pops unlocks a new {{icon|building slots}} building slot, it is possible to stack city population capacity arbitrarily high (given enough time) by building {{icon|aqueduct}} aqueducts if the total of the percentage modifiers is at least '''150%''' - possible if focusing on stacking modifiers and improving the the territory/province by the midgame - which will make each {{icon|aqueduct}} aqueduct give {{green|+10}} population capacity, enough to create another building slot to build another {{icon|aqueduct}} aqueduct once the population capacity has been filled. It is usually strongest to do this in the {{icon|capital}} capital, which has a number of bonuses that makes each individual pop even more productive.

If a territory exceeds its {{icon|pop cap}} population capacity, it will get one instance of the '''Overpopulation''' modifier for every pop over the {{icon|pop cap}} population capacity, giving:
* {{icon|migration attraction}} {{red|-4}} Migration Attraction
* {{icon|happiness}} {{red|-4%}} Local Population Happiness
* {{icon|migration speed}} {{green|+3}} Migration Speed
* {{icon|pop growth}} {{red|-0.03%}} Local Population Growth
The {{icon|population}} population of a territory with any significant amount of overpopulation will therefore usually quickly fall back down through {{icon|migration speed}} migration and population death, while population growth from natural growth, immigration, and {{icon|enslavement efficiency}} enslavement will be quickly stalled, providing an effective soft cap on the population that a territory can sustainably have. It is generally rarely worth having an overpopulated territory, unless the territory only needs to go slightly over the {{icon|pop cap}} population capacity to meet the threshold to produce another [[trade goods|trade good]].

==人口期望比例==
{{SVersion|2.0}}
Every territory has a desired '''optimal ratio''' for each pop class that the population of the territory will slowly drift towards, determined by the sum of all pop ratio modifiers ({{icon|noble ratio}} '''Noble Desired Ratio''', {{icon|citizen ratio}} '''Citizen Desired Ratio''', {{icon|freeman ratio}} '''Freeman Desired Ratio''', {{icon|tribesman ratio}} '''Tribesman Desired Ratio''', and {{icon|slave ratio}} '''Slave Desired Ratio''') that apply to the territory and its owner. Some modifiers are local and apply only to a single territory ('''Local Desired Ratio'''), some apply to all territories in a country ('''National Desired Ratio'''), and some apply to all territories with {{icon|city}} city status in a country ('''Desired Ratio in Cities''').

Despite what it might suggest, a modifier that increases the ratio of a pop class by a certain percentage does not necessarily actually increase the optimal ratio of that pop class by that amount. Instead, the optimal ratio of each pop class is normalized by summing up all the desired ratio modifiers for that class (with a minimum desired ratio of 0) and dividing it by the total desired ratios over all 5 pop classes:
: <math>\text{Optimal Ratio for Class}=\frac{\text{Desired Ratio for Class}}{\text{Desired Noble Ratio} + \text{Desired Citizen Ratio} + \text{Desired Freeman Ratio} + \text{Desired Tribesman Ratio} + \text{Desired Slave Ratio}} \cdot 100%</math>


For instance, in a {{icon|settlement}} settlement owned by a [[monarchy]] with no other modifiers, there is a {{icon|slave ratio}} {{green|+10%}} Local Slave Desired Ratio modifier along with a {{icon|citizen ratio}} {{green|+2.5%}} Local Citizen Desired Ratio from the territory rank and a {{icon|freeman ratio}} {{green|+2.5%}} National Freeman Desired Ratio modifier from the government form that is applied. This gives a final desired ratio of <math>2.5/(2.5 + 2.5 + 10) \cdot 100% = 16%</math> for {{icon|citizens}} citizens and {{icon|freemen}} freemen and a final desired ratio of <math>10/(2.5 + 2.5 + 10) \cdot 100% = 66%</math> for {{icon|slaves}} slaves. One major effect of the way that the optimal ratio is calculated is that the effect of further modifiers is high when there are few desired ratio modifiers to begin with, but decreases rapidly as more and more are applied.

The [[territory rank|rank]] of a territory is one of the main factors that affect the desired class ratios of a territory:
{| 
|- 
| {{icon|settlement}} '''Settlements''' 
| {{icon|city}} '''Cities'''
| {{icon|metropolis}} '''Metropolises'''
|- style="vertical-align:top;"
| 
* {{icon|citizen ratio}} {{green|+2.5%}} Local Citizen Desired Ratio
* {{icon|slave ratio}} {{green|+10%}} Local Slave Desired Ratio
| 
* {{icon|noble ratio}} {{green|+15%}} Local Noble Desired Ratio
* {{icon|citizen ratio}} {{green|+30%}} Local Citizen Desired Ratio
* {{icon|freeman ratio}} {{green|+40%}} Local Freeman Desired Ratio
* {{icon|slave ratio}} {{green|+25%}} Local Slave Desired Ratio
| 
* {{icon|noble ratio}} {{green|+10%}} Local Noble Desired Ratio
* {{icon|citizen ratio}} {{green|+30%}} Local Citizen Desired Ratio
* {{icon|freeman ratio}} {{green|+30%}} Local Freeman Desired Ratio
* {{icon|slave ratio}} {{green|+15%}} Local Slave Desired Ratio
|}

Each overall {{icon|government}} government form also applies further modifiers to pop ratios in each territory:
{| 
|- 
| '''[[Monarchy]]'''
| '''[[Republic]]'''
| '''[[Tribal]]'''
|- style="vertical-align:top;"
| 
* {{icon|freeman ratio}} {{green|+2.5%}} National Freeman Desired Ratio
| 
* {{icon|freeman ratio}} {{green|+2.5%}} National Freeman Desired Ratio
* {{icon|citizen ratio}} {{green|+5%}} Desired Citizen Ratio in Cities
* {{icon|freeman ratio}} {{green|+7.5%}} Desired Freemen Ratio in Cities
| 
* {{icon|noble ratio}} {{red|-7%}} National Noble Desired Ratio
* {{icon|tribesman ratio}} {{green|+10%}} National Tribesmen Desired Ratio
|}

Several buildings, particularly those in {{icon|city}} cities and {{icon|metropolis}} metropolises, also modify the desired class ratios locally:
* {{icon|noble ratio}} {{green|+5%}} Local Noble Desired Ratio per {{icon|academy}} Academy ({{icon|city}} city building)
* {{icon|citizen ratio}} {{green|+10%}} Local Citizen Desired Ratio per {{icon|court of law}} Court of Law ({{icon|city}} city building)
* {{icon|freeman ratio}} {{green|+10%}} Local Freemen Desired Ratio per {{icon|forum}} Forum ({{icon|city}} city building)
* {{icon|slave ratio}} {{green|+10%}} Local Slave Desired Ratio per {{icon|mill}} Mill ({{icon|city}} city building)
* {{icon|freeman ratio}} {{green|+15%}} Local Freemen Desired Ratio with a {{icon|barracks}} Barracks ({{icon|settlement}} settlement building)
* {{icon|citizen ratio}} {{red|-2.5%}} Local Citizen Desired Ratio with a {{icon|tribal settlement}} Tribal Settlement ({{icon|settlement}} settlement building)

Certain [[laws]] and [[government]] types can also affect the desired ratio of pop classes across all territories with {{icon|city}} city status in a country, including:
{{MultiColumn|
* {{icon|freeman ratio}} {{green|+10%}} Desired Freemen Ratio in Cities for an {{icon|government}} [[Monarchy|Aristocratic Monarchy]]
* {{icon|freeman ratio}} {{green|+10%}} Desired Freemen Ratio in Cities for a {{icon|government}} [[Monarchy|Stratocratic Monarchy]]
* {{icon|citizen ratio}} {{green|+10%}} Desired Citizen Ratio in Cities with the {{icon|law}} Relax Citizenship Status [[Monarchy]] law
* {{icon|freeman ratio}} {{green|+10%}} Desired Freemen Ratio in Cities with the {{icon|law}} Courts for Landowners [[Monarchy]] law
* {{icon|slave ratio}} {{green|+15%}} Desired Slaves Ratio in Cities with the {{icon|law}} Slave Treatment Sanctions [[Republic]] law 
* {{icon|citizen ratio}} {{green|+10%}} Desired Citizen Ratio in Cities with the {{icon|law}} Cultural Primacy [[Republic]] law
* {{icon|freeman ratio}} {{green|+10%}} Desired Freemen Ratio in Cities with the {{icon|law}} Manumittance Policy [[Republic]] law
* {{icon|slave ratio}} {{green|+15%}} Desired Slaves Ratio in Cities with the {{icon|law}} Lex Fufia Caninia {{flag|Rome|0}} [[Rome|Roman]] [[Republic]] law 
* {{icon|citizen ratio}} {{green|+10%}} Desired Citizen Ratio in Cities with the {{icon|law}} Lex Plautia Papiria {{flag|Rome|0}} [[Rome|Roman]] [[Republic]] law
* {{icon|freeman ratio}} {{green|+10%}} Desired Freemen Ratio in Cities with the {{icon|law}} Lex Aelia Sentia {{flag|Rome|0}} [[Rome|Roman]] [[Republic]] law
* {{icon|freeman ratio}} {{green|+20%}} Desired Freemen Ratio in Cities with the {{icon|law}} Rights of Man [[Tribal]] law
* {{icon|citizen ratio}} {{green|+20%}} Desired Citizen Ratio in Cities with the {{icon|law}} Rights of Birth [[Tribal]] law
|2}}

A number of other local modifiers can also change the pop ratios of a territory.

The overall effect of these modifiers is that {{icon|citizens}} citizens and especially {{icon|nobles}} nobles are found almost exclusively in {{icon|city}} cities and {{icon|metropolis}} metropolises, as well as to a lesser extent in {{icon|capital}} capitals (even those that are {{icon|settlement}} settlements), while {{icon|settlement}} settlements will be dominated by {{icon|slaves}} slaves and either a smattering of {{icon|citizens}} citizens and {{icon|freemen}} freemen for [[republic]]s and [[monarchy|monarchies]] or {{icon|tribesmen}} tribesmen for [[tribal]] countries. Increasing the movement and migration of pops from settlements to cities will therefore result in an overall higher proportion of {{icon|nobles}} nobles and {{icon|citizens}} citizens in the country, which is generally recommended as {{icon|nobles}} nobles and {{icon|citizens}} citizens are the only source of {{icon|research points}} 研究点 which is needed to keep up in technology.

===晋升与降级===
{{SVersion|2.0}}
The pop class structure of territories will change over time to approach the optimal ratio through {{icon|promotion}} '''promotion''' and {{icon|demotion}} '''demotion'''. Every territory will have one pop promoting and one pop demoting at a time until the actual pop class ratio converges with the optimal ratios for each class in that territory, as long as there are pops that are eligible to be promoted or demoted. Pops cannot promote or demote if they are currently {{icon|assimilation}} assimilating or {{icon|conversion}} converting; as well, pops cannot promote past the assigned [[civic rights|civic rights]] of its culture, which is particularly important when trying to promote pops into {{icon|citizens}} citizens and {{icon|nobles}} nobles. {{icon|slaves}} Slave promotion (to {{icon|freemen}} freemen) can be blocked on a territory-specific basis using the '''Slave Promotion Allowed''' toggle in the territory population interface at the cost of {{icon|slave happiness}} {{red|-24%}} slave happiness, which can be useful to prop up {{icon|local tax}} tax income and increase the amount of [[trade goods]] produced, though fewer pops of other classes will mean less {{icon|manpower}} 人力 and particularly {{icon|research points}} 研究点 and {{icon|trade routes}} trade routes.

As with other pop activities, promotion and demotion of pops gain progress each month, with the exact amount of progress determined by the {{icon|promotion}} '''Pop Promotion Speed''' and {{icon|demotion}} '''Pop Demotion Speed''' modifiers, respectively. Once progress reaches 100%, the pop will promote by one level or demote by one level and another pop will begin to promote or demote, if there are any other pops that can do so. Note that pops will only ever promote or demote by one level regardless of how far the territory's current pop classes are from the optimal ratio - for instance, a {{icon|slaves}} slave will need to promote three times before it can become a {{icon|nobles}} noble, even if there are currently no nobles in the territory. As an exception, while {{icon|tribesmen}} tribesmen while promote to {{icon|freemen}} freemen and demote to {{icon|slaves}} slaves as expected, {{icon|freemen}} freemen will demote directly down to {{icon|slaves}} slave status rather than passing through {{icon|tribesmen}} tribesmen first. Similarly, {{icon|slaves}} slaves can promote to both {{icon|freemen}} freemen or {{icon|tribesmen}} tribesmen, depending on the current situation.

The base {{icon|promotion}} promotion and {{icon|demotion}} demotion speed depends on the original class of the pop (not the class it is promoting/demoting to), with {{icon|nobles}} nobles and {{icon|tribesmen}} tribesmen particularly slow to promote or demote:
{{MultiColumn| 
'''Promotion speed'''
* {{icon|citizens}} Citizen Promoting: {{green|+6}}
* {{icon|freemen}} Freeman Promoting: {{green|+6}}
* {{icon|tribesmen}} Tribesman Promoting: {{green|+4}}
* {{icon|slaves}} Slave Promoting: {{green|+10}}
'''Demotion speed'''
* {{icon|nobles}} Noble Demoting: {{green|+2}}
* {{icon|citizens}} Citizen Demoting: {{green|+4}}
* {{icon|freemen}} Freeman Demoting: {{green|+6}}
* {{icon|tribesmen}} Tribesman Demoting: {{green|+2}}
|2}}

{{icon|promotion}} Promotion speed is then affected by many other modifiers, including:
{{MultiColumn|
* {{green|+2.5%}} for each {{icon|population}} pop in the territory
* {{green|+2.5%}} for each {{icon|trade routes}} trade route in the province (including both import and export routes)
* {{green|+2.5%}} for each {{icon|road}} outgoing road
* {{red|-10%}} for each point of {{icon|unrest}} unrest
* {{red|-25%}} in {{icon|settlement}} settlements
* {{green|+10%}} in {{icon|metropolis}} metropolises
* {{green|+25%}} in the {{icon|capital}} capital
* {{green|+10%}} in {{icon|province capital}} province capitals
* {{green|+10%}} for {{icon|port}} ports
* {{green|+25%}} with a capital surplus of {{icon|livestock}} livestock
* {{green|+15%}} per governor {{icon|finesse}} finesse plus a base of {{green|+15%}} with the [[File:Policy_social_mobility.png|28px]] Social Mobility [[governor policy]]
* {{green|+10%}} with the {{icon|invention}} Granted Manumission {{icon|civ}} Civic invention
* {{green|+15%}} with the {{icon|invention}} Urban Planning {{icon|civ}} Civic invention
* {{green|+20%}} with the {{icon|invention}} Gradated Citizenship {{icon|civ}} Civic invention
* {{green|+25%}} for {{icon|government}} [[Tribal|Federated Tribe]]s
* {{green|+0.025}} for each point of positive {{icon|centralization}} centralization
* {{green|+6}} with the {{icon|law}} Military Settlement Policy [[Republic]] law
* {{green|+6}} with the {{icon|law}} Lex Servilia Glaucia {{flag|Rome|0}} [[Rome|Roman]] [[Republic]] law
* {{green|+2}} with the {{icon|law}} Sedentary Bureaucracy [[Tribal]] law
* {{green|+25%}} if the country is {{icon|religion}} [[Jain]]
* {{green|+10%}} with {{flag|Messenia|0}} Helot [[Heritage]] ([[Messenia]])
* {{green|+10%}} with Bosporan [[Heritage]]
* {{red|-10%}} with {{flag|Elea|0}} Elean [[Heritage]] ([[Elea]])
* {{green|+0.20%}} for each point of [[revanchism]]
|2}}

Similarly, modifiers to {{icon|demotion}} demotion speed include:
{{MultiColumn|
* {{green|+2.5%}} for each {{icon|population}} pop in the territory
* {{green|+1%}} for each {{icon|road}} outgoing road
* {{green|+10%}} for each point of {{icon|unrest}} unrest
* {{green|+33%}} if the {{icon|food}} food supply of the province reaches 0 and population is dying of starvation
* {{green|+10%}} if the territory is currently occupied or under siege
* {{green|+10%}} if the territory was recently plundered by {{icon|pirates}} pirates
* {{green|+5%}} if the {{icon|religion}} dominant religion is not the state religion
* {{green|+15%}} per governor {{icon|finesse}} finesse plus a base of {{green|+15%}} with the [[File:Policy_social_mobility.png|28px]] Social Mobility [[governor policy]]
* {{green|+10%}} per governor {{icon|finesse}} finesse plus a base of {{green|+10%}} with the [[File:Harsh_treatment.png|28px]] Harsh Treatment [[governor policy]]
* {{green|+6}} with the {{icon|law}} Relocation Policy [[Republic]] law
* {{green|+6}} with the {{icon|law}} Lex Papia de Peregrinis {{flag|Rome|0}} [[Rome|Roman]] [[Republic]] law
|2}}
<br>

== 参考资料 ==
<references/>

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