Trade is an elementary part of the roleplay. There are several trade goods, most are required for recruiting troops, building ships or developing your realm. You do not have income or the need to construct anything, but for roleplay matters like improving sewers etc some ressources are necessary.
- A city (red dot) gives two "pieces" of its resource. A town (black dot) gives one "piece".
- Every city and town automatically supplies itself with 1 food, which is in use to supply the population. If you use it for something else, your population starves.

Coal (Needed for "Industry", Smiths, Ships)
Copper (Basic metal for weapons and armour)
Iron (Basic metal for weapons and armour)
Steel (Can be made of Iron and Coal)
Silver (Generates Wealth, used for coins or jewelry, luxury good)
Gold (Generates Wealth, used for coins or jewelry, luxury good)
Mithril (Highest Quality metal for armour)

Wood (Basic construction resource, also for ships)
Stone (Basic construction resource, required for castle upkeep)
Marble (Fine construction resource, luxury good)

Food (Food for people, needed for sieges, standing armies)
Horses (Needed for quality cavalry, dwarves have boars/goats instead)
Wool (Needed for clothing and producing textiles)
Textiles (Needs Wool to be produced, needed for clothing and ships, also required for a standing army)
Silk (Creates 2 Textile, luxury good)
Vellum (Needed for adminsitrations and stuff - paper, luxury good)
Slaves (Use your fantasy)
Dyes (Luxury good)
Spices (Creates 2 Food, luxury good)

Luxury Goods: They are needed for rule, having them increases popularity of the own and conquered population for the rulership.

Wood - Ships: 1 Wood supports a maximum of 20 ships, each kind.

Slaves: 1 Slave resource represents 10.000 Slaves.

Production/Refinemnt:
Steel: 1 Coal and 1 Iron can be made to 1 Steel.
Textiles: 1 Wool can be made to 1 Textile in settlement of Textile production.
Explanation for Cities: If you have a city which produces Textiles, means they can produce two (2), you need only one (1) Wool to get the resource of the city. Wool for textiles is the only refinement which works this way.
Silk and Dyes: 1 Silk and 1 Dyes can be made to 4 Textile.

If you have a port and a tradeship you can trade via the sea way. One tradeship per good per trade partner. So if you want to trade two goods with one partner, you need two traders.
On the land way you can only trade with neighbours, except you have the passing rights of the realms between yours and the desired trade partner. Do not forget: Only taken realms are a barrier.