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.
- Main article: Alliance (Civ5)
Declarations of Friendship fill the role of alliances. AI civilizations will offer more favorable trades after declaring friendship with a partner, and can also form Research Agreements. Declaring friendship does not prevent either civ from denouncing or declaring war on its partner, however.
- Main article: Alliance (Civ6)
Forming an 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 alliances that provide various and evolving benefits.
Civilization: Beyond Earth
- Main article: Alliance (CivBE)
Civilization: Call to Power
- Main article: Alliance (CTP1)
Call to Power II
- Main article: Alliance (CTP2)
Sid Meier's Alpha Centauri
- Main article: Alliance (SMAC)
Alliance is not present in (or the article has not been created for) the following games :
|Civilization II||Alliance (Civ2)|
|Civilization III||Alliance (Civ3)|
|Civilization IV||Alliance (Civ4)|
|Civilization Revolution||Alliance (CivRev)|
|Civilization Revolution 2||Alliance (CivRev2)|
|Civilization IV: Colonization||Alliance (Civ4Col)|