Trading Center

The Trading Center is the building used to conduct trade with city-states that have already been discovered through the Exploration Office, contacted through the Diplomatic Office, and opened for trade routes. It is an important support building because it lets the player import goods that are difficult or inefficient to produce locally, and export surplus goods for profit or logistical flexibility.

Trade is organized through trade contracts. A contract selects either an import or export pool from the target city-state, then chooses a specific trade good, its settled price, how many packages will be sent or received each trade cycle, how many trade cycles the contract will last, and which Storage will be used to supply or receive the goods. The total amount exchanged over the life of the contract is the trade volume, calculated from package size, package count, and number of cycles.

A few key rules determine how Trading Center contracts behave:

• The length of a trade cycle depends on the distance to the target city-state, usually ranging from 1 to 4 days.
• Every trade cycle, the selected number of packages is exchanged at 0:00.
• Trade goods have fixed package sizes of 5, 8, 10, 15, or 25, with more processed or rarer goods generally appearing in smaller packages.
• The package size of a given trade good does not change between city-states.
• For each prosperity level of the city-state, one additional package can be traded per cycle.
• If the chosen Storage does not contain the goods needed for export, or cannot receive the imported goods, that trade cycle fails and nothing is exchanged.

Pricing is based on two values: the standard price and the settled price. The standard price of trading goods fluctuates from day to day, while the settled price is the actual contract price. For imports, relations with the target city-state increase the price; for exports, relations decrease it. When a new contract is created, the settled price is locked in for the entire duration of that contract. When a contract is renewed, the settled price is recalculated from the current standard price, so it is best to begin export contracts when the standard price is high and import contracts when it is low.

The available trade goods are not fixed forever. Each city-state maintains pools of import and export goods that rotate regularly, with the biomes in that city-state’s territory influencing which goods appear. Some goods are always available for a given city-state, and those can be checked on its page.

If the selected Storage is destroyed or moved, the trade contract does not have to be discarded immediately. The delivery storage can be reassigned from the trade interface by selecting the ongoing contract and changing the storage from the details view. Renewal is the only point at which the storage selection can be changed in the contract setup itself.