Diplomacy

Diplomacy is the section of UC that concerns Federations, Lords, and Vassals.

Lord
Lords are people who your Empire belongs under, and while under it the lord may give you food or money to support you and in return you give him Empire Level. Good lords often give every day unless circumstances prevents it. Lords usually look for taxing empires because they give more empire level than those using other incomes.

Vassal
Vassals are empires under you, they post op for you when needed and gives you empire level. In return you can give them support in money, food, or actual money.

Federation/Clan
Federation and Clan works the same way as Lords and Vassals but they do not help in money as much. Instead they post op more which helps you defend.