Diplomacy is one of the greatest tools at a leader's disposal - knowing when to befriend others and when to declare war can be the difference between a successful empire and one that crumbles before its foes. There are also many ways to take advantage of your allies, and benefit from your enemies. Almost all of this is done via the Diplomacy Screen (Hotkey F7).
The Diplomacy screen shows all empires in the game and your relationship to them: War, Cold War, Peace, or Alliance. Empires that have not yet been met cannot be negotiated with and are blurred-out in the back right of the screen, and empires that have since fallen are in the back left. It is also possible to see the Diplomatic Relationships of other empires you have met by clicking on the yellow arrow icon next to their name, allowing you to see the Diplomacy Screen from their point of view. This can help you know how one empire feels about another, which can be useful when deciding how to act; for example, if an empire proposes an alliance with you, but the are at war with an empire that is right next to you, accepting might not be the best idea as it would make you a target.
From the Diplomacy screen, you can select an empire and perform a number of diplomatic actions - granted you have the Influence necessary to do so. Diplomatic relationships and actions also provide Diplomatic Points which are needed to win the Diplomatic Victory.
Many interactions with other empires - diplomatic or not - are affected by the main Diplomatic Status you have with them.
War is automatically declared if an Empire attacks armies inside their owner's region, including sieging or attacking a City. With the exceptions of proposing a Truce, no diplomatic actions can be take between two empires at war. Being at war with another empire provides 1 Diplomatic Point per turn . The Roving Clans are unable to declare war due to their "Make Trade Not War" trait, but can still be at war with an empire if that empire declares war on them.
During war, armies of the two empires are able to attack each other anywhere on the map, and it is possible for empires to take each other's cities by force. The only way to end a war is for one empire to completely destroy the other, or for the two empires to agree to a Truce.
A Truce is a temporary diplomatic status that exists between two empires that agreed to end a war before either was destroyed. Empires in a state of truce cannot attack each other for a period of several turns (20 on Normal speed) without breaking the truce and paying an additional cost in Influence , and the cost of declaring War during a truce is greatly increased. Peace or Alliance cannot be proposed during a state of truce, and a truce provides 1 Diplomatic Point per turn . After the truce ends, the two empires automatically move to a state of Cold War.
During this period, empires can attack each other's armies without declaring war on each other so long as one empire's army isn't attacking the units of another empire within a region that empire controls - such an action will require a declaration of War. Cold War provides 1 Diplomatic Point per turn .
Cold War can be thought of as the "default" status for the many empires in the game; when two empires meet for the first time, they are automatically placed in Cold War, and in the absence of other states such as a War Declaration or Peace Agreement, the empires will fall into Cold War.
While in a Peace Treaty, the two empires cannot attack each other without breaking the treaty and paying an additional cost in Influence , and both empires will not suffer from Retaliation Damage inflicted by their defensive structures, such as the Tower of Truth or Ward of Auriga. Trade Routes can be established between the two empires where applicable, and a number of treaties meant to benefit both empires become available for proposal, as well as allowing the free trade of Resources, Stockpiles, Fortresses, and Technology between the empires. Peace provides 2 Diplomatic Points per turn .
Proposing a Peace Treaty requires the Diplomat's Manse Technology.
An Alliance provides all the advantages of a Peace Treaty, and many more. When an Alliance comes into effect, any Closed Border treaties are automatically broken and more cannot come into effect, Map Exchange and Shared Vision treaties are automatically ratified for free, and Allies are able to use each other's roads for troop movement as though they were their own. Allies also earn Influence if they kill a unit that belongs to an Empire that their Ally is at War or Cold War with. An Alliance also gives a certain amount of Influence each turn, with the amount increasing the longer the alliance lasts. An Alliance also provides 4 Diplomatic Points per turn (5 with ELCP).
Proposing an Alliance requires the Hospitality Den Technology.
As the game progresses and you perform different actions, the opinions other empires in the game have about you will change accordingly. The reason for these changes in opinion are varied, and can be due to direct actions you have taken such as attacking their armies or entering peace with their friend, or due to the general state of your empire, such as your global score or the size of your standing army. Every empire responds to different things to a different degree, so while one empire may feel very threatened by you having a powerful army, another empire may not care. An empire's attitude towards you is displayed under their name on the Diplomacy screen, with the reasons for that attitude being shown by hovering over it.
There are four 'axes' along which these attitudes lie: Envy, Fear, Trust, and War. Each axis has five levels on them, with the attitude that is the strongest being the one that's shown as that empire's attitude. The centerpoint of each of these axes is "Indifferent", meaning that you haven't made enough of an impact on that empire for them to have formed a strong opinion of you, which is usually the case after having just met an empire.
Envy is a measure of how much an empire envies the overall state of yours, with the different attitudes from least to most envious being: Mocking, Pitying, Indifferent, Mildly Jealous, Envious. The way this attitude determines how an empire acts can vary greatly; a Mocking empire may either take you under your wing out of pity or try to conquer you because they don't think you pose a threat, while an Envious empire may want to enter an alliance with you to benefit from your empire or attack you out of spite.
Fear is a measure of how much an empire fears you, and is largely determined by the difference in your empire's military might. The different attitudes from least to most fearful are: Unafraid, Dismissive, Indifferent, Worried, Terrified. Generally speaking, empires that are not fearful of you will be much more willing to go to war with you than an empire that does fear you.
Trust is a measure of how much an empire trusts you to act in their benefit, and is a little more complicated to influence, but actions such as attacking them or siding with their enemies will decrease trust, while going to war with an empire's enemy while you're at peace with them will greatly increase trust, as well as long-lasting peace between your empires. From least to most trusting are: Leery, Careful, Indifferent, Trusting, Blood Brothers. Empires that are Leery are going to be much harder to negotiate with, while those that you have attained Blood Brother status with will generally be much more open to trade and negotiation.
The War axis is a little odd compared to the others, as it only comes into effect when two empires are at war, and rather than showing how an empire feels about you, shows how that empire feels about the progress of the war. This is affected by the outcome of battles, significantly affected by the conquest of Fortresses or Cities, and how long the war has been going on. The attitudes towards the war from least to most optimistic are: Exhausted, Nervous, Indifferent, Confident, and Triumphant. An empire's attitude during war mostly shows how that empire is going to respond to a Truce proposal; an empire that is feeling Triumphant will require a significant amount of tribute from the other empire to accept a truce, often requesting cities, while an empire that is Exhausted will give in to a lot of demands to secure a Truce.
After meeting an empire, it is possible to enter Negotiations with them by clicking on their leader in the Diplomacy screen. This will bring you to a screen where you are able to set the Terms of the Negotiation, how much Influence those terms will cost each empire, and how the other empire feels about the terms being set. All terms have an Influence cost to them, and that cost must be paid by whichever empire is proposing that term. Things such as Resources, Stockpiles, and Technologies have a flat cost for each one proposed, such that proposing an offer of 1 cost the same amount of as proposing 10,000 , but proposing 1 and 1 will cost twice as much . Treaties, however, have a cost that varies greatly depending on a number of factors, primarily your diplomatic standing with the other empire. It should also be noted that some treaties are classified as Diplomatic Declarations - such as "Close Borders" - and are marked by an exclamation mark; these terms usually cost more Influence and damage relationships with the receiving Empire, but are not open to negotiation by the targeted Empire, and simply come into effect.
Once the terms have been set, it is possible to see how an AI Empire will respond to those terms by the "Contract terms" gauge just under the "Term Options" window. If the bar is red, then the terms will be refused, but if the bar is green, it will be accepted. How far the bar has been filled in either direction shows how strongly the empire feels about the terms, and hovering over a term in the Term Options window will give a flashing preview of how much that term will adjust the gauge one way or another. Because the Empire will accept a proposal as long as the gauge is even slightly in the green, it is recommended to set the terms as close to neutral as possible unless you are trying to gain an empire's favor by making trades strongly weighed in their favor.
Additionally, other empires may propose something to you, at which point you may either refuse their terms (usually damaging their opinion of you), accept, or offer a counter-proposal which opens the Negotiation screen. The latter of these is generally recommended, since opposing empires will usually propose terms strongly in their favor, so you may be able to balance the offer without offending them as a flat refusal might.
The Terms available for Negotiation are also strongly affected by your diplomatic status with the other empire, with many treaties being exclusive to certain statuses.
Treaties are the primary means by which negotiations between empires take place, and are broken down into two main groups: Diplomatic Treaties, and Diplomatic Declarations. Diplomatic Treaties are generally beneficial for one or both parties, and include things such as entering peace or making a truce, but require that both parties be in agreement for them to come into effect. As such, Diplomatic Treaties are open to negotiation and may need to be made with additional offerings of other terms for both empires to find the terms agreeable. Diplomatic Declarations, however, are not open to negotiations, and simply take effect once the empire making the declaration pays the Influence cost to do so. Declarations are made by themselves, and do not come with any additional terms.
- Truce: Enter a negotiation with an Empire you're at War with to end the war and enter a Truce status with them.
- Peace: Enter a negotiation with an Empire you're at Cold War with to move to Peace. Requires Diplomat's Manse.
- Alliance: Enter a negotiation with an Empire you're at Cold War with or in Peace with to enter an Alliance. Requires Hospitality Den.
- Declaration of War on: Offer to enter a state of War with an Empire that the Empire you're negotiating with is also at War with, or try to convince an Empire to enter War with another Empire that you are at War with.
- Map Exchange: Maps between the two Empires are shared. Only available while in Peace treaty or Alliance with target Empire. Automatically activated upon entering an Alliance with an Empire.
- Vision and Map Exchange: Vision and Maps between the two Empires are shared. Only available while in Peace treaty or Alliance with target Empire. Automatically activated upon entering an Alliance with an empire.
- Commercial Agreement: Increases the Dust gained from Trade Routes with the targeted Empire by 1% per Turn , up to 20%. Only available while in Peace treaty or Alliance with target Empire.
- Research Agreement: Increase the Science gained from Trade Routes with the targeted Empire by 1% per Turn , up to 20%. Only available while in Peace treaty or Alliance with target Empire.
- Open Borders: Enter a negotiation with an Empire that has closed their borders to you to have them re-open their borders, or offer it as term during negotiation.
- Market Ban Removal: Enter a negotiation with an Empire to remove a Market Ban from either them if you placed the ban, or yourself if you were the target of the ban.
- Black Spot Removal: Offer to remove the Black Spot from an Empire you have placed it on. Exclusive to the Morgawr due to their "The Black Spot" trait.
- Cold War: Enter a state of Cold War with an Empire you are either at Peace or in an Alliance with.
- Peace: Enter a state of Peace with an Empire you are in an Alliance with.
- Declaration of War: Enter War with the targeted Empire. Not available to the Roving Clans due to their "Make Trade Not War" trait.
- Close Borders: Armies controlled by the targeted Empire cannot enter regions you control. Doesn't affect Privateers. Only available while in Cold War or Peace Treaty with targeted Empire. Automatically canceled upon entering War or an Alliance with the targeted Empire.
- Compliment: Increase the Influence cost of negative treaties (Close Borders, War, etc.) and decrease the cost of positive treaties (Peace, Alliance, etc.). Effect lasts 10 turns depending on the Game Speed, with an optimal effect at mid-term.
- Warning: Decrease the Influence cost of negative treaties and increase the cots of positive treaties. Effects last around 10 turns depending on the Game Speed, with an optimal effect at mid-term.
- Map Embargo: Cancels an existing Map Exchange with the targeted Empire.
- Vision and Map Embargo: Cancels an existing Vision and Map Exchange with the targeted Empire.
- Force Truce: Force a truce treaty on an Empire you're at War with. Exclusive to the Drakken due to their "Diplomatic Pressure" trait. (With ELCP, Force Truce can not be used on the same Empire for 5 turns after the Drakken has declared war on that Empire)
- Force Peace: Force a Peace treaty on an Empire you're at Cold War with. Exclusive to the Drakken due to their "Diplomatic Pressure" trait.
- Force Alliance: Force an Alliance on an Empire you're at Cold War or in Peace with. Exclusive to the Drakken due to their "Diplomatic Pressure" trait.
- Market Ban: Prevents the targeted empire from using the Marketplace. Exclusive to the Roving Clans due to their "Keys to the Market" trait, and also cannot be used against factions with this trait. (With ELCP, Market Ban can not be used for 2 turns on the same Empire after the ban was removed.
- Market Ban Nullification: Force the removal of a Market Ban from your Empire for a high Influence cost.
- Inflation: Reduces Trade Route Dust and Science income of the targeted Empire by 50%, and can only be used against an Empire you are at war with. Exclusive to the Roving Clans, and is unlocked by acquiring the Money Talks technology from completing their Faction Questline. Entering a Truce automatically removes Inflation.
- Inflation Nullification: Removes Inflation from an Empire that has been targeted by it. This Declaration can only be used by the Empire that placed the Inflation.
- Black Spot: Place the Black Spot on the targeted Empire you are at War or Cold War with. An Empire with the Black Spot can have its units attacked by any empire, regardless of diplomatic status, and killing their units rewards the attacker with Dust . The Black Spot can only be placed on one Empire at a time. Exclusive to the Morgawr due to their "The Black Spot" trait. Entering a Truce, Peace treaty, or Alliance automatically removes the Black Spot.
- Black Spot Nullification: Force the removal of the Black Spot from your Empire.
Offer various resources for trade during negotiations. The resources that can be offered this way are Dust , Strategic Resources, Luxury Resources, and Pearls . However, these can only be offered while negotiating a Diplomatic Treaty with another empire (not making a Declaration), or while you are in a Peace Treaty or Alliance with the target empire.
Offer Stockpiles up for trade during negotiations. Does not apply to faction-specific stockpiles, such as the Necrophages' Recycled Stockpiles. Similar to Resources, these can only be offered while negotiating a Diplomatic Treaty with another empire (not making a Declaration), or while you are in a Peace Treaty or Alliance with the target empire.
Offer a City (excluding your capital or last city) during negotiations. This can only be used while negotiating for a Truce.
Offer a Fortress for trade during negotiations. As with Resources, these can only be offered while negotiating a Diplomatic Treaty with another empire (not making a Declaration), or while you are in a Peace Treaty or Alliance with the target empire.
Offer Technology for trade during negotiations. Does not apply to faction-specific technologies, such as faction unit designs or technologies gained from Faction Quests. As with Resources, these can only be offered while negotiating a Diplomatic Treaty with another empire (not making a Declaration), or while you are in a Peace Treaty or Alliance with the target empire.