Endless Space Wiki
Main article: Factions


In Endless Space, you will be able to interact with other factions in game through Diplomacy. Specific technologies will help you improve your relations and give you more possibilities for your Empire to interact with its neighbour. Indeed, you will be able to:

  • Offer Peace
  • Declare War
  • Cease Fire
  • Open Borders
  • Cooperation Agreement
  • Alliance: create an Alliance, invite to an Alliance, or leave an Alliance.

The specific technologies required to be researched are:

Cold War[]


This is by default your diplomatic status at the beginning of the game. It means that you can attack any enemy fleet in your territory or be attacked outside of frontiers without declaring war.

The Cold War state will prevent any movement in another player's territory. If however, one of your fleets happens to cross an enemy's territory, it will remain stuck or be vulnerable to any attack. You will have to either Declare War or offer an Open Border agreement to be able to proceed to any action with this fleet.



You will need to declare war to be able to attack inside another faction’s frontiers or invade their systems. You do not need any technology to declare War to a faction.

Note that the Cravers can only interact with other faction through Diplomacy with a War declaration (Refer to "Eternal War" faction trait).

Peace Treaty[]


You will need at least a peace treaty to propose other treaties and exchanges. Being at peace will not prevent opponents from declaring war.

Note that the Cravers faction cannot be at Peace with anyone because of their "Eternal War" faction trait.

If your opponent is an AI, you’ll have to check their attitude factor to guess how they might act towards your empire:

  • hate
  • hostile
  • suspicious
  • neutral
  • friendly
  • warm
  • very close

From "Hostile" to "Hate" behaviour, the AI will not accept a Peace Treaty.



All members of the same Alliance will share the same diplomatic relations with factions outside that alliance. When creating or entering an alliance the worst relations’ statuses are kept: If the alliance was at war with another faction but you were at peace with it, when you join the Alliance you will also automatically be at war with that other faction. This also works the other way around…

How it works[]

Here are the different steps of the Alliance process:

  1. Someone in the alliance decides to pass a treaty with someone outside the alliance. Possibilities: Peace, War, Invite to Alliance, Cease Fire.
  2. A request is sent to all other members of the Alliance
  3. Other players reply to the treaty: I agree / I disagree
  4. Those who agreed with it stay in the Alliance and those who disagree leave the Alliance.

Worst Status[]

At the end of the turn, if a member of the Alliance did not reply to a request (or simply ignored it), by default, it is considered that he agrees and consequently, the player will stay in the Alliance. If there are desynchronization issues regarding the Alliance status, the worst status is chosen.