Influence

**Influence** () is one of the primary yields in *Humankind*, likely representing cultural influence or pressure. In the game, it is an important currency for creating Cities and Outposts, buyout Constructibles in Outposts, enacting Civics, claiming Cultural Wonders, interacting with Independent People and spreading cultural pressure to other Territories.

## Influence Production

A the start of the game **Influence** is obtained through hunting Animals in Neolithic Era (Deer +5**Influence**, Bear +10**Influence**, Mammoth +20**Influence**) and Curiosities.

After settling in Ancient Era, every Empire will produce its own **Influence**. The primary source of **Influence** come from the Populations in the Empire's Cities:

* If the City's Stability is at **Settled** or **Calm** (91-100%), each  will generate +2**Influence**.
* If the City's Stability is at **Strained** (30-90%), each  will generate +1**Influence**.
* If the City's Stability is at **Mutinous** (0-29%), each  will not generate **Influence**.

High Liberty with Emblematic Quarters (+2**Influence** per EQ per Liberty level)

Envoys sent to foreign Empires will generate **Influence** to both the host Empire and the Envoy's Empire (called **Cultural Bridges** on the **Influence** Income Breakdown).

The Embassy provides +3**Influence** per Era per adjacent District.

Besides Population, the Commons Quarter, certain Infrastructures, the following Tenets and Civics will also contribute to the Empire's **Influence**.

Tenets:

* Shelter the True Oracles (Tier 1) (+1**Influence** on Mountains)
* Proselytize Daily (Tier 3) (+2**Influence** on Commons Quarters))

Civics:

* Founding Myths (Natural Right +5**Influence** on Main Plaza)
* Religious Tolerance (Open-Minded, +3**Influence** on Territories following State Religion)
* Cultural Blessing (either, calculate what benefits most)
* Artistic Ownership (same)
* Slaves (War Slaves, +1**Influence** on Garrisons)

## Influence Spread Mechanic

Every Empire's **Influence** can spread across the map and influence other Territories through its **Influence** production. Influence spreading is a **passive** process that is not directly controlled by the Empires.

* Both **Faith** and **Influence** spread largely follows the same mechanics.

### Basic Influence Spread Mechanics

The spreading of Influence is measured in **Territory-based **Influence** production** and can be checked via the **Society Screen**.

Every Territory will produce a certain value of Influence for the Empire that **owns** it, known as **Influence Production**. The produced Influence will then spread, and give pressure to other Territories. Every Territory, in turn, will receive ****Influence**** from both local sources and distant Territories; the sum of both is the **Influence of an Empire** on a given Territory.

Every Empire's Influence on a Territory is calculated as a **percentage** of the total ****Influence**** this Territory received. If another Empire's Influence on a given Territory is **20% higher in **Influence**** than the current Empire's Influence, then the Territory will gradually fall into the other Empire's **Sphere of Influence**.

### Distance impacts on Influence Spread

The spread of ****Influence**** across the map decreases with **Territory-based distances**. A Territory would receive stronger Influence Pressure from adjacent Territories, and reduced Pressure from Territories further away. This distance based decrease is calculated as following:

Influence Pressure on distant Territory = Local Influence Production \* Territory Distance ^ (-1.25)

"Territory Distance" and also be understand as "Number of Territories the spreading Faith needs to pass through."

This formula means every Territory will always have a 100% Influence pressure on adjacent Territories, and much less than 100% on Territories further away.

Note that a Territory can only spread ****Influence**** to other Territories **connected by Roads**. If two Territories are adjacent to each other, but not connected by Roads - such as they only share a water border, or the access between the two are blocked by mountains or high cliffs - then the Influence spread between these two Territories will be **O**.

* For islandic Territories and Territories across the ocean, they will not naturally receive Influence pressure from outside sources beyond the sea. Only by building at least one **Harbor** or **Airport** in these Territories can they receive outside Influence.

### Trade and Diplomacy impacts on Influence Spread

The starting and destination Territories of a Trade Route will receive **less reduction** on Influence Pressure.

This Influence Spread though Trade is a one-way process, and **will only spread the culture of the Exporting Empire into the Importing Empire**. This means a major Exporting Empire with various Luxuries and Strategics, especially if they built Influence-produce Districts in the Resource-rich Territories, will more likely to spread its culture and ideology to the rest of world.

The rules of Influence Spread via Trade Routes are as of below:

* For a Land Route, the Exporting Territory's Influence Pressure to the Importing Territory **will only receive 50% distance reduction** - in terms of formula, instead of a Distance^(-1.25), it becomes (Distance/2)^(-1.25) - as if **the distance between the two are halved**.
* For a Naval Route connected by two Harbors, the Importing Territory **will receive 100% Influence Pressure** from the Exporting Territory, as if the two are **adjacent**.
* For an Air Route connected by two Airports, the Importing Territory **will receive 100% Influence Pressure** from the Exporting Territory, as if the two are **adjacent**.
* For Naval Routes, if one end of the naval Trade Route **doesn't have a Harbor** - only has a Trade Port instead - then the "unconnected" rule will apply, and Influence will not spread between these two Territories.
* Only the starting and the destination Territories will have their Influence be impacted by Trade Routes. Territories that the Trade Route passing by along the way will not receive anything extra.

If two Empire are at War, then Influence/culture will not spread between the two. However, if one Empire captures another Empire's city, the occupying Empire can spread its Influence to the conquered city rather easily, as the other Empire cannot spread its Influence to this city anymore.

## Sphere of Influence

All the Territories that are under one Empire's influence make up this Empire's **Sphere of Influence**. A **Sphere of Influence** can be much bigger or smaller than an Empire's territorial extent, depending on the Empire's **Influence** production ability.

**Sphere of Influence** served as an important modifier to the interactions between Empires, and between Empires and Independent Peoples. The related effects and bonuses include:

* If an Empire belongs to another Empire's Sphere of Influence, this Empire will have a more friendly Attitude towards the influencing Empire.
* If an Empire belongs to another Empire's Sphere of Influence, and declares war to the influencing Empire, this Empire will lose more War Support per turn.
* If an Independent People belongs to an Empire's Sphere of Influence, the Empire can patronize the Independent People with less cost.
* In addition, an Empire that has Territories within other's Sphere of Influence will constantly receive Osmosis Events.

## Osmosis Event

**Osmosis Events** will happen when a City is **under the influence of another Empire**. The other Empire's culture, ideas, or technologies, can spread into Territories within the Sphere of Influence, and taken note by the local people; the ruler of the Empire being influenced can then decided to accept the new idea/technology or not.

There are two types of Osmosis Events, **Civics Osmosis** and **Science Osmosis**.

### Civics Osmosis

A **Civic Osmosis** can happen if a City falls into the influence of another Empire, and the foreign Empire has a different choice on a given Civic.

* A notification window will pop up on the City's banner, saying that the local population demanded changes concerning a certain civic.
* The Empire can choose to **Revoke** the current civic choice. The civic will instantly change to the demanded civic choice with no additional costs. Additionally, the Ideological Proximity with the foreign Empire will increase.
* The Empire can also choose to **Refuse** this foreign interference. The civic in question will stay unchanged, but the City will fall into Defiant status (-50Stability ) for 10turns.
* Certain Civics have a diplomatic effect, marked by a **small globe symbol** (🌐) on the Civic icon. Refusing to change such a Civic will create a special Grievance for the foreign Empire, and they can demand the refusing Empire to change it.

### Science Osmosis

A **Science Osmosis** can happen if a City falls into the influence of another Empire, and the foreign Empire researched a Technology you haven't unlocked.

* A notification window will pop up on the City's banner, saying that exchanges between the City and the foreign culture could lead to a technological breakthrough.
* The Empire can choose to **Unlock** the technology instantly at the cost of Money. The technology will be fully researched afterwards.
* The Empire can also dismiss the offer and choose to **Boost Research** instead. The foreign knowledge will be converted into a one-time boost of Science, which will automatically be invested in whatever the technology that is currently being researched.