Influence is a score that Great Powers can invest in other nations, the primary use for which is adding nations into Spheres of Influence.
Influence is built over time, and may be selectively prioritized in particular nations.
 Sphere of Influence: Benefits
Only a Great Power can add a country to a Sphere of Influence.
- If any country is part of another country’s Sphere of Influence, a portion of its Internal Market is joined with its master country and all other members of that Sphere of Influence, making a larger and more versatile Internal Market. Goods produced in one country may be purchased by the other without Tariffs and before the Demand from higher Prestige buyers on the World Market can buy them away.
- Provides prestige when a nation is added to your sphere of influence
- Nations that are sphered are likely to respond to all diplomatic requests such as alliances, military access, etc.
- Enables some unification events and decisions.
A newly-created satellite (or a dominion if overseas) is automatically placed in its mother country's sphere of influence, although it can be removed by other powers.
 Sphere of Influence: Drawbacks
- Adding nations to the Sphere can reduce tariff income since goods are purchased internally
- Nations with large artisan populations (such as China) can outproduce national factories and put them out of business
 The Race For Influence
Influence is spent on nations automatically, based on priorities set on the Diplomacy screen. Influence will be divided among all nations with a priority set, with one share going to nations with Low priority, two shares to nations with Middle priority, and three shares to nations with High priority. If your embassy has been banned by a competing power, that nation is ignored for purposes of influence, so the influence isn't wasted. Note that if only one nation has a priority set, it will receive all influence regardless of how high the priority is.
A nation's raw influence per day is altered by percentage modifiers on each nation. These modifiers are added, so a -50% modifier and a +75% modifier would work out to a +25% adjustment to daily influence gain being applied.
- Power: The percentage of the influencing nation's total score that it is higher than the target nation's total score is given as a bonus to the influencing nation. This has a maximum +100% bonus, against nations with a score of zero, but can become a penalty in the rare case that a great power has a lower score than a non-great power.
- Vassals: A nation gets +100% to relations with its puppets and dominions.
- Relations: A nation's relations with the target nation is divided by ten and applied as a bonus or penalty (allowing for a maximum +20% bonus, or a -20% penalty if relations are poor).
- Neighbor: A nation that shares a border with the nation attempting to influence it grants a +50% bonus.
- Other Continent: A nation on a different continent than the nation attempting to influence it gives a -50% penalty. Note that it is possible to have both the Neighbor bonus and Other Continent penalty.
- Other Foreign Investors: If a nation has invested in the target nation, a -50% penalty will be applied to all other influencers, unless they reduce the penalty by investing in the target nation themselves. If multiple nations have made investments, each suffers a penalty equal to -50%*(1 - Nation'sInvestment/TotalForeignInvestment). For example, if Nation A has invested £10,000 and Nation B has invested £20,000, then Nation A will suffer a 33.3% penalty, and Nation B a 16.6% penalty. Once a nation is suffering from this penalty, the only way it will ever disappear completely is if the other nation's investment is somehow removed.
- Population: Influencing nations get tremendous penalties in target nations with populations over 10 million (such as China and its larger substates), making them effectively impossible to sphere.
 Using Influence
Influence points are determined by national ranking, and provide the following abilities:
- Increase Opinion (50 Influence) - increases a nation's opinion of your nation to the next tier. Also gives +25 relations.
- Decrease Opinion (50 Influence) - decreases a nation's opinion of another Great Power to the tier below.
- Add to Sphere (100 Influence, requires Friendly opinion and the nation not to be in a sphere) - Adds a nation to your sphere of influence.
- Remove from Sphere (100 Influence, requires Friendly opinion and the nation to be in a sphere) - Removes a nation from another Great Power's sphere of influence.
- Expel Advisors (50 Influence) - Removes all the influence of another Great Power. Particularly effective if they have a high amount of influence.
- Ban Embassy (65 Influence) - Removes all the influence of another Great Power, and prevents them gaining any more for a year.
- Discredit (25 Influence) - Slows the rate of influence gain of another Great Power by 75% (additive with other bonuses) for six months.
Decrease Opinion, Expel Advisors, Ban Embassy and Discredit can only be used on Great Powers with opinions at the same or lower tier (so a Cordial nation cannot ban a Friendly embassy).
Once a nation has 100 Influence with another nation, any further Influence investments will be spent on reducing the Influence reserves of competing nations.
Opinion is a measure, separate to relations that ranks how close or far a Great Powers are to holding a power in a sphere of influence. Influence abilities that affect other Great Powers must be done on ones with equal or lower opinion to you.
The tiers, in descending order:
- In Sphere
Secondary powers that break free of a Sphere of Influence via an event will immediately drop down to Opposed opinion.