"Diplomatic Capital is the currency of diplomacy. It represents a mixture of your leader's power, experience, and prestige on the global stage. You earn Diplomatic Capital locally from wonders and special buildings, and you earn it internationally when you allow other leaders initiate agreements. Likewise, you spend Diplomatic Capital when you initiate and maintain agreements with other leaders. You can also spend it to level up or change your leader's Personality Traits, which will improve its effects"
- In-game Civilopedia
Diplomatic Capital, like the Faith resource in the Gods & Kings expansion for Civilization V, is used to gain special perks in the form of Personality Traits and Diplomatic Agreements. Unlike Religious Beliefs in Gods & Kings, however, two or more leaders can have the same traits if they want to and it is now not a "first come, first serve" style of game-play. Diplomatic Capital can also be used to buy units and buildings, in the same way Energy can be used. However, the resource cost to purchase is higher when using than when using .
Factions that use Diplomatic Capital in their unique Personality Trait
There are three factions now that incorporate Diplomatic Capital in their unique Personality Trait:
- Brasilia, which earns a +1 for each unit killed in combat.
- INTEGR, which gets a 50% discount on initiating new agreements and a 25% discount to purchasing units and buildings using .
- Pan-Asian Cooperative, which gets wonders for free that produce +6 instead of +5 .
What Diplomatic Capital can be spent on
Personality traits (Rising Tide). There are four types potential Personality Traits that offer very important perks. The first one is unique to each faction and the other three are open to all factions. The three other types of Personality Traits need to be bought with Diplomatic Capital and all Personality Traits can be upgraded twice using Diplomatic Capital; also Personality Traits that were already bought can be changed by spending Diplomatic Capital. The cost for each upgrade, new trait, or change in trait starts at 100 and goes up after every purchase. There are 10 Traits for every type of Personality Trait, each with a unique perk and unique potential Diplomatic Agreements that other leaders and can use if they "purchase" them with Diplomatic Capital.
Foreign Policies (Rising Tide). Diplomatic Agreements can be initiated and maintained using Diplomatic Capital, and usually offer very situational perks. The cost of initiating one can be any where from 25 to more than 250 depending on the power of the agreement. The maintenance cost per turn can be anywhere from 3 to 75 , depending on the power of the agreement.
Purchasing Units and Buildings. When in the purchasing menu for the City Overview, there are two tabs: "Purchase with ", and "Purchase with ". The cost of purchasing Units and buildings with Diplomatic Capital is about 50% more than the cost of purchasing the same units with Energy across the board.
How to increase Diplomatic Capital income
- Trade Depot, +2
- Old Earth Relic, +2
- Alien Preserve, +2
- Network, +2
- Gene Garden, +3
- Feedsite Hub, +3
- Holosuite, +3
- Civil Crèche, +3