In Endless Space 2, empires can negotiate treaties, deals, and diplomatic agreements from the Diplomacy Screen (F6). Reaching more peaceful states and researching certain techs in the Empire Development tree allow for more powerful agreements, all the way to Alliances, which can share a Joint Victory. Support for the Pacifist party encourages and benefits from friendly diplomacy, while Religious and Militaristic Empires can benefit from entering Wars.
Diplomatic Status
Cold war
All empires start in cold war with one another. They may attack fleets to engage in Fleet Combat in neutral territory, or if the opposing fleet is in a colonized system. Aggressive actions during this phase, including attacking fleets, displeases the Empire and prompts response. Exploring the territory of another empire during Cold War carries the risk of attack by their fleets, but many empires will allow exploration Ships to pass in the early portions of the game. Empires at Peace can return to Cold War. Empires in Cold War can trade resources in the Negotiation Screen, which costs Influence.
War
During War, Fleets can battle in any territory, and Systems can be invaded with Manpower through a Ground Battle. if the Ground Battle is won, the System is captured.
Empires with Militarists as their dominant Political Party automatically receive a forced law that gives a bonus to happiness for each empire at war.
Peace
Once Empires have made peace, additional diplomatic actions become available. These include Map sharing and Trade agreements.
Empires with Pacifists are their main Political Party have the Forced Law active that gives a bonus to FIDS for each Empire at Peace.
Alliance
Multiple Major Factions can bind together as an Alliance, which is then pledged to work as a team. This has multiple consequences: [1]
- Shared Diplomatic relations: Any war declaration from one Faction applies to the whole Alliance; however, each member has the option to step out of the Alliance when a war is declared by an Alliance member
- Faction Pact Bonus: Factions in an Alliance can sign a specific pact with one other faction in the Alliance. This grants an effect linked to their ally’s faction, which improves over time (up to a max).
- Coordination Tool: To communicate with allied Empires, you can use the small icon on the bottom right of the End Turn button in the galaxy view. This allows you to leave marks at specific points in the Galaxy to notify your allies of your intentions.
Allied Empires share vision and can win a Joint Victory. Requirements for some victory types, however, increase proportional to the number of players in the Alliance.
Empires with Pacifists as their main Political Party have the Forced Law active that gives an additional bonus to FIDS for each Empire in the Alliance. Please note you need at least 4 empires in the game to form an Alliance.
Relationships
In addition to the treaty status, each other Empire has a relationship status, which varies based on what they think of you and what their goals are.
- Reserved: We just met you
- Cautious
- Welcoming: We desire peace.
- Friendly: We have been at peace for a long time, trade agreements
- Cordial
- Wounded : As allies we asked for your military help but you didn't send any.
- Sneaky: We were friends, but saw an opportunity. We are stronger than you.
- Hostile: We did not receive any tribute from you.
Pressure
Unless they are at war, any two Empires will exert Diplomatic Pressure on each other based on several factors:
- Differences in Score
- Size of Influence zone (borders friction on the smaller one)
- Systems covered by other Influence zone
- Contextual diplomacy choices
Score modifiers are summed up to give final score modifier known as Pressure Trend and War Momentum (respectively) that ranges from -10 to +10 per turn. These are represented by Blue/Orange bars on the Diplomacy screen.
.png "Diplomatic Pressure (positive).png (1.13 MB)")
.png "Diplomatic Pressure (negative).png (1.13 MB)")
During Cold War and Peace
Pressure Trend (change over turns): Ranges from -10 to +10 per turn.
- Score Difference *
- Diplomatic Treaties
- Diplomatic Choices
- Borders Friction *
- Systems Covered by Influence *
- Hacking
* For the above 3 marked factors, acquisition of certain diplomatic pressure modifying things will increase pressure points towards enemy player.
- Z'vali's "Spirit" trait - +25% Diplomatic Pressure towards enemy
- Amoeba Law - +50% Diplomatic Pressure towards enemy
- Citadel of Demography - +50% Diplomatic Pressure towards enemy [Possible reward from Preserver of Nations, a Tier 5 Deed in the Empire Development research quadrant.]
| Source | Description |
|---|---|
| Score Difference | Difference between player's scores. Scores of each players can be checked by hovering mouse cursor over bottom left "End Turn" button. The greater the score difference between 2 players, the higher the pressure points.
Total Acquirable Pressure Points
|
| Diplomatic Treaties | Forcing a diplomatic choice "Bureaucratic Imbroglio" on other player.
|
| Diplomatic Choices | When enemy asks player to stop attacking/invading.
|
| Borders Friction | When influence borders of 2 star systems, each belonging to different players touch each other on the galaxy view screen. The amount of pressure point is determined by the net influence difference between systems whose influence zones overlap.
Total Acquirable Pressure Points
|
| Systems Covered by Influence | When influence borders cover different player's star system.
|
| Hacking | [Only applicable to Penumbra DLC] Hacking enemy's star system.
|
During War
War Momentum (change over turns): Ranges from -10 to +10 per turn.
- Fleet battles
- Ground battles
- Systems blockaded
When War Momentum reaches 80% or 20%, a Force Truce offer may be sent by the victor or loser. It costs Influence to reject such an offer, and the offer is only sent to one member of an Alliance to accept/decline. (The mechanic is meant to be an anti-snowball system that allows losers to recover during Truce between wars.)
During any point during the war, you may also make a normal Truce offer through the Diplomacy screen. Available Terms include resources and Systems that aren't under Blockade. But the AI's willingness to accept/decline depends on War Momentum, Mood, and how egregious your Truce offer seems to them.
| Source | Description | Score Modified |
|---|---|---|
| Fleet Battles | Battles between fleets of 2 players. Winning adds points and losing deducts points. | "Details Unknown" |
| Ground Battles | Battles between the ground troops of 2 players when invading a star system during sieging. Winning adds points and losing deducts points. |
"Details Unknown" |
| Systems Blockaded | When a fleet performs Guard action on opposing player's star system and block it. Player blocking enemy's star system adds points and enemy blocking player's star system deducts points. |
Player blocking Enemy: +0.1 per Star System Enemy blocking Player: -0.1 per Star System |
Deals
Most deals come with a flat cost of Influence to enact. Some cost much more than others, and the cost scales with time.
- Peace: available only during Cold War
- Truce: available only during War.
- Alliance: available during Peace. (Size limited to no more than half the remaining factions in the game)
- Map Sharing: A one-sided agreement. The receiver gains all of the map explored so far by the donor.
- Close Borders: Empires at peace can close their borders to one another without returning to Cold War.
- Trade Dust
- Trade Luxury Resources
- Trade Strategic Resources
[Agreements also have Influence Upkeep costs to maintain them each turn, and will be automatically cancelled if either side fails to maintain them.]
- Trade Agreement: If Trading Companies are built, Subsidiaries for both Empires will be shared, allowing an extra trade route from each HQ to the Subsidiaries, often with much larger distance bonuses than trade within one's empire.
- Science Agreement
- Co-operative Agreement (Faction-specific buff shared with other faction.)
- Cancel Agreement (Trade/Science/Co-operative)
Demands
Once an Empire has been sufficiently "Influenced", Demands can be made. The availability of demands can be seen on the bar in the Negotiation Screen. Terms include things such as Dust, resources, technology, or Economic Tribute(Dust/Science donation over a set number of turns).
Tribute/Gifts
Other empires will sometimes demand Tribute or Gifts.
When a tribute is demanded, a donation significant enough to be accepted must be made in that turn. Making the tribute results in a positive boost to the relationship, while neglecting the tribute will worsen relations. An empire may request multiple tributes within a short number of turns, so it is usually a good idea to make peace after paying the tribute. If peace cannot be made, such as with The Cravers, paying the tribute may not be worthwhile.
Gifts also work to reduce the effects of Pressure, delaying the ability for the enemy to make an official Demand. Gifts may also be requested to improve the opinion of the other empire during Force Peace.