The Congress of Humankind allows all the active participants in a game to have their say in global matters. It is divided into three aspects: Laws votes, International Crisis votes, and Global Doctrines.
Any Empire can unlock the Congress of Humankind, provided they fulfill its requirements: Having reached the Early Modern era, having built their own Embassy, and having met all other Empires. Whenever one Empire unlocks the Congress, all other Empires will meet each other – even those they hadn’t yet encountered.
Empires will take turns to periodically submit a Civic of their choice to the Congress, so that other Empires can vote and decide which of that Civic’s choices should be the dominant one worldwide.
At the end of the Voting Session, whichever choice garnered the most votes will be offered to all Empires, to be enacted for free through a special Osmosis event on their Capital. Accepting the new choice is free, but refusing it costs as much Influence as it would cost to cancel a Civic choice.
Another function of the Congress of Humankind is to arbitrate International Crises. Whenever an Empire has Demands against another, a refusal no longer means being forced to declare War. Instead, the Crisis can be elevated to the Congress as a last-ditch effort to stop the War. Upon this escalation, all other Empires will be able to vote using their Leverage for the Empire whose Demands they think should be fulfilled.
At the end of the voting period for a Crisis, the loser of the vote will drop all their Demands and will be asked anew if they now accept the winning side’s own Demands, or if they still want to go to War. Ignoring the vote of the Congress and moving ahead with War will cause all other Empires will gain Grievances and Leverage against the aggressor, to help encourage them to see reason.
International Sway is a value that represents the voting power of an Empire in the Congress of Humankind. Every turn your Sway is calculated based on the sum of Leverage you have against other Empires, any permanent bonuses you may have garnered over time, and any temporary boosts gained by bribing other Empires for a given vote.
Bribing other Empires into lending you more voting power can temporarily increase your Sway for a specific vote. In order to bribe an Empire, you need to have enough Leverage against them. You will be able to purchase a set amount of Bribe actions from an Empire for each vote; the number of Bribe boosts available depends on the target Empire’s original Sway at the beginning of the Voting Session.
Since Bribe boosts apply only for a specific vote, your voting power may be different between the Laws screen and each individual Crisis Vote.
Global Doctrines are the extension of each Empire’s own Ideology axis to the global stage. On the Doctrine screen of the Congress of Humankind, you will be able to see the ideological position of all current factions: Empires, but also Independent Peoples who currently own a City. Taken together, all ideological positions define a global consensus, which is the average of the position of all factions.
Before allowing Doctrine effects to activate, Empires need to collectively unlock each individual Doctrine axis by spending Influence. For a single Empire, the cost of each following unlock action grows; so while a single Empire may single-handedly unlock a Doctrine axis, it will be much cheaper overall if everyone pitches in.
Once a Doctrine axis is unlocked, however, it cannot be locked again, and all Empires in the game will have to live with its effects. Doctrine effects update on a set timer, visible on the screen. You can see if a shift in the world’s Ideologies will enable a new effect when the timer resets.
It is important to note that the effects will apply to everyone, whether they want them or not. If you think that it would be more beneficial to you for the world to move towards a different Ideology, you can vote accordingly on the Congress’ Laws, use your Agent’s Manipulate a City action, enter Cultural Agreements with Independent Peoples, or even increase your overall Influence to cause Civics Backlashes on your neighbors.