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In the Civilization and Call to Power games and Sid Meier's Alpha Centauri, an alliance is a special relationship formed between two civilizations for mutual benefit. It is usually the closest level of diplomatic relations available in each game.

Civilization V

Declarations of Friendship fill the role of alliances. AI leaders will offer more favorable trades after declaring friendship with a partner, and can also form Research Agreements. Declaring friendship does not prevent either partner from denouncing or declaring war on the other, however.

Civilization VI

Forming an Alliance Alliance with another civilization prevents both allies from denouncing or declaring war on each other. It also provides Open Borders and Shared Visibility, allowing each ally to see everything on the map that the other's units and cities can see. The Rise and Fall expansion adds new types of Alliance Alliances that provide various and evolving benefits.

Civilization: Beyond Earth

Civilization: Call to Power

Call to Power II

Sid Meier's Alpha Centauri‎

Other games

Alliance is not present in (or the article has not been created for) the following games :

Game Article
Civilization Alliance (Civ1)
Civilization II Alliance (Civ2)
Civilization III Alliance (Civ3)
Civilization IV Alliance (Civ4)
Civilization VII Alliance (Civ7)
Civilization Revolution Alliance (CivRev)
Civilization Revolution 2 Alliance (CivRev2)
CivWorld Alliance (CivWorld)
Freeciv Alliance (Freeciv)
C-evo Alliance (C-evo)
Sid Meier's Colonization Alliance (Col)
FreeCol Alliance (FreeCol)
Civilization IV: Colonization Alliance (Civ4Col)
Starships Alliance (Starships)

Future technology (CivRev)
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