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Diplomatic Treaties
When two independent lords negotiate their interests or sign diplomatic treaties after a war, the treaty is simplified compared to others, focusing only on taxes and military service. Each quarter, a certain amount of tax must be paid to the other party, and in times of war, a specific proportion of military support must be provided.
The game scenario begins in January 1067. At this time, William the Conqueror has transitioned from being the Duke of Normandy under France to becoming the King of England. However, he remains a vassal to France and thus has signed a diplomatic treaty with them. Quarterly taxes are required to be paid, and in case of war declared by the King of France, knights need to be provided for battle. Of course, William also has the option to annul this diplomatic treaty.
System Contracts
The Holy Roman Empire is not a unified country but rather an alliance formed by independent lords and their vassals. Only independent lords can join this system.
After completing policy reforms within the Holy Roman Empire contract system, it becomes possible for members within the empire to sign system contracts with the emperor. These members are independent lords within the empire who can pay taxes to the emperor and provide military service as well as perform other functions such as appointing electors or hereditary electors.
Hereditary Electors: By default yes; when set otherwise and an elector dies without an heir, allowing automatic reappointment by the emperor
Voting Rights: Only members with voting rights can participate in imperial meetings
Forced Alliance: When declaring war as Emperor, member states are obligated to provide 100% knight participation
Vassalage Contracts
Compared to other contracts, vassalage contracts have more extensive terms.
Each vassal will have one particular clause highlighted during contract generation that they care about most - satisfying this clause earns double approval points.
Automatic Title Promotion: When a lord accumulates enough prestige and territory holdings they can automatically advance in rank without requiring approval from their superior lord
Capital Defense: If an overlord's capital is attacked then subordinate lords who have signed this contract must unconditionally provide 100% knight support
Stone Castles: Default castles are made of wood; stone castles offer higher defensive efficiency
Territorial Protection: Overlords cannot reclaim territories held by their vassals
Voting Rights: Vassals with voting rights may participate in decisions when overlords' authority is low or decisions require voting
Hereditary Titles: By default yes; if not set so then upon death titles will degrade until reaching lowest level
Below these ranks there exist honor knights, knights,and nobles which are roles held by individuals without land holdings.
Negotiation & Diplomacy
In essence it involves exchanging benefits where superiors offer incentives for vassals' cooperation in order to obtain desired benefits themselves through either concessions or negotiations. Once negotiated agreements are signed there is a 20-year freeze period before renegotiation becomes possible again. Different clauses require different levels of approval which can be obtained through high credit ratings used for accruing favors promised lands etc., or through territorial claims among other methods.
Your credibility affects your promises & commitments - higher credibility means greater value while lower credibility renders them ineffective eventually losing all value altogether.
Favors owed carry over but commitments do so probabilistically.
In some scenarios you may seek support via negotiation e.g., accusing another lord at Imperial meetings where you might exchange promises/favors for votes even during elections for successor emperors/empresses.
Due lack reform no access System Contracts within HRE yet
Exchanging promise favor vote support
Some features remain undeveloped like negotiating independence into becoming one's own liege signing feudal/diplomatic treaties etc..