Diplomacy (Civ4)

As Civilization IV progresses and your units explore the world around them, you will meet the leaders of the other civilizations around you. Each leader is different: some are warlike; others, peaceful. Some are backstabbing liars; others are (usually) honest. You'll have to learn how to deal with these characters: some you'll fight right away; others you'll negotiate with - at least until it's time to destroy them...

You can accomplish a lot through diplomacy. You can trade technologies, resources, maps, gold, and even cities. You can form mutual protection pacts; you can declare war; you can negotiate peace settlements. Success in Civilization IV depends as much on your diplomatic skills as it does on your martial and management prowess.

Leaders[]

Each leader has his or her own agenda. They, too, seek to achieve victory - some through force of arms, others through technological prowess, others through cultural domination. You'll get clues to their intentions as the game progresses - the more warlike leaders will usually not trade anything of military value, the knowledge-focused leaders will seek advanced technologies, and so forth.

Leader Attitudes: During the game, each leader will form an opinion of you: how great a threat you are to their civilization, whether you have fought them in the past, whether you have allied with their enemies, how much you can be trusted to keep your word, etc. Leader attitudes come in five flavors: friendly, pleased, cautious, annoyed, and furious. The more a leader likes you, the more likely he or she is to be willing to trade with you, and the better deal you'll get. You may be able to trade with hostile leaders, but you're likely to pay a stiff price for whatever you get.
Refusing to Talk: Sometimes a particularly angry leader won't speak to you at all. This occurs most often when your civilizations are at war. Check back again in several turns - by then he or she may have cooled off enough to be willing to speak, especially if his or her military situation has declined.

Opening Diplomacy[]

You can open diplomacy from the diplomacy screen, or by clicking on the leader's name in the "score box" on the main screen. Occasionally, a leader might open negotiations with you. When diplomacy begins, the diplomacy screen appears.

Diplomatic Options[]

When diplomacy opens, you (and the other leaders) usually have several choices available:

Declare War: The polite way to open hostilities. (The less polite way is to march your units into the enemy's territory without an open borders agreement.)
Offer Peace: Available only if you're at war.
Trade: Try to trade stuff with the other civilization. This takes you to the trade table.
Review Ongoing Deals: Some "annual" deals continue over time (see below). This option lets you review any such deals you have in place with the leader.
Exit: End the diplomatic session.

Making Trade Offers[]

On the trade table, all of your tradable items are listed in the right-hand column, while the other leader's stuff is in the left-hand column. To make an offer, click on one (or more) items in your column, and one (or more) items in the other leader's column, and then click on the "make offer" button. If the leader agrees, the deal is done. If not, you can exit diplomacy or try another deal.

If you click only on an item in the other leader's column but not on anything in your column, you are "demanding tribute:" ordering the leader to give you the item for free. He or she may decline, of course, and in either case, his opinion of you will probably decline. If you click only on an item in your column but none in the other leader's, you are giving the leader that item for free, as a "goodwill gesture." Leaders never refuse goodwill gestures. Goodwill gestures often cause the leader to raise his or her opinion of you.

Responding to Offers[]

When another leader makes you an offer, you must choose to refuse or accept the offer. If you accept, the trade occurs immediately. If you decline, the other leader may ask you to make a counter-offer, may end diplomacy, or may declare war on you.

Untradeable Items[]

Often you will see items in the leader's column that are colored red. This indicates that the leader will not (or cannot) trade these items with you, so don't bother asking.

Technological Requirements for Trade[]

You need access to certain technologies to trade some items; at the beginning of the game, your diplomatic options are severely limited. Both sides do not need to know the required technology, but at least one of the traders must. You cannot trade technology, for example, until either you or your trading partner knows the Alphabet technology.

Trading Types[]

There are two distinct kinds of items you can trade: "immediate" items or "annual" items. Immediate items can only be traded for other immediate items, and annuals only for other annuals. You are free to trade any items within a group - technology for gold and a world map, for instance, since they're all immediate items - but you can't trade an immediate item or items for one or more annuals.

Immediate Items: These are items that are exchanged immediately. That is, the deals have no duration. Immediate items include: lump sum of gold, maps, technology, peace treaties, cities, and so on.
Annual Trade Items: Annual trades last for a minimum of 10 turns. They can continue for longer than 10 turns if both sides agree, but neither side can cancel an annual trade before 10 turns are up, except by declaration of war. Annual items include: resources, gold per turn.

Tradable Things[]

Gold, Lump Sum - Immediate - A chunk of gold. 1 gold. 15 gold. A billion-billion gold.
Gold, Per Turn - Annual - A certain number of gold per turn: 2 gold/turn. 30 gold/turn. This lasts a minimum of 10 turns. Note that you are obligated to pay this gold no matter what: empty treasury, anarchy, etc. Your treasurer will automatically disband units and buildings as necessary to fulfill your obligations.
World Map - Immediate - All of the territory explored by your partner is now visible on your main map and vice versa.
Open Borders - Annual - Your units can now move freely through your partner's territory, and vice versa. If you declare war against a civilization you have an open borders agreement with, all of your units are removed from his territory, and all of his units are removed from yours. Furthermore, your cities' trade routes extend to include those civs which whom you have Open Borders. Since foreign trade routes are much more lucrative than domestic ones, signing Open Borders can significantly increase the commerce of your cities. Various buildings and civics can increase this income even more.
Defensive Pact - Annual - If either of your civilizations is attacked by a third party, the other civilization automatically declares war on the attacker. This agreement is nullified if either of the signatories attacks anybody.
Permanent Alliance - Immediate - Your two civilizations essentially become one nation with two rulers. You each continue to have control over your units and cities, but you share everything else: resources, technologies, maps, and victory or defeat. If one declares war, the other automatically does so as well. If one signs a treaty, the other is bound by it.
Technology - Immediate - You immediately learn the technology that has been traded to you.
Resources - Annual - If a resource is traded to you, you get all of its benefits for as long as the agreement is in place. The trader loses all of the benefits, unless he or she has more than one. (For instance, if somebody trades you Iron, you can then construct any military unit that requires Iron. The trader can no longer produce such units, unless he's got another source of Iron.)
Declare War with - Immediate - One civilization asks another to declare war on a third. A leader can ask another leader to declare war on a civilization that the first civilization is not at war with, but the other leader will usually charge through the nose for doing so.
Cities - Immediate - Your opponent agrees to give you one or more of his or her cities. If you have open borders with the other civilization, all units remain in place. If not, the units in the city are shifted back to their own territory. It is extremely rare for a leader to give up a city unless under great duress.
Adopt - Immediate - One civilization asks another to change civics. Each leader has a favorite civic-type - Catherine, for example, likes Hereditary Rule. Leaders like you better if you are employing their favorite civic.
Convert - Immediate - One civilization asks another civilization to change its state religion to match the first civilization's state religion. Religious differences between civilizations cause a lot of tension: adopting another civilization's religion is an excellent way to firm up relations with that civilization.
Declare Peace - Special - Peace breaks out between you and your opponent. All units are immediately vacated from each other's terrain. Peace lasts for a minimum of 10 turns. You can only trade peace for gold or technology.
Declare Cease Fire - Special - Peace breaks out between you and your opponent. All units are immediately vacated from each other's terrain. There is no duration for this cease fire - either side can immediately declare war again. Nothing can be combined with a cease fire deal.