Trade is a gameplay mechanic in Empire: Total War.
Engaging in trade raises revenue for a nation and improves diplomatic relations with others. How much revenue made depends on the amount of goods the faction is selling, the prices of the goods, as well as the wealthiness of the factions that are buying its goods. As the amount made from trade is directly related to the wealth of factions and their regions, trade becomes more profitable over time.
Unless interrupted through raids or blockades, trade is always profitable, regardless of trading partners or the direction of the flow of goods.
The Trade TabEdit
The Trade Tab can be accessed through the Policies button. It lists the current prices of all commodities, as well as the amount of goods recieved from plantations and trade theatres. Finally, it lists all factions the player's faction is trading with, what goods are being sold to them, whether trading routes are being raided or blockaded, and how much total income the faction is recieving from trade.
There are eight commodities in Empire: Total War: Fur, Ivory, Spices, Cotton, Sugar, Tea, Coffee, and Tobacco. Fur can only be obtained through Fur-Traders and their variants: buildings that may only be built in specific locations, generally in northern regions of the world map. Sugar may be obtained by controlling trade nodes in the Coast of Brazil, and may also be gathered at plantations built in the Carribean, South America, and India. Spice is similar to sugar in where plantations for it can be built, but it can be collected from the trade nodes in the East Indies. Ivory cannot be collected from buildings and is only available from the Ivory Coast and Straits of Madagascar trade nodes. Tea plantations may only be grown in India, and Tobacco plantations may only be grown in the Americas.
Each commodity has its own price that fluctuates independently from the others. Generally, the more of a good there is available, the lower its price. Sometimes prices fluctuate independently of this, however. Having a balanced access of multiple commodities help ensure that income does not change greatly over time due to price crashes.
Establishing Trade Routes and Obtaining GoodsEdit
Trade routes can be establish on land or by sea. In order for a sea trade route to be established, a Trading Port must be constructed; in turn, the port must have road access to the faction capital. Hovering the cursor over the trade route displays how much wealth it is bringing in, to which particular factions. Trading Ports can only handle so much volume, and if a region is making too many goods but lacks sufficient trade ports (or if they're not upgraded enough), then any excess goods are not sold and are left to waste.
Trade routes may be plundered by ships, which remove a portion of the route's income and fills the raiding faction's coffers, instead. Only trade routes that are being utilized by factions hostile to the raiding faction may be targeted. Ships may also choose to blockade trade ports belonging to hostile factions, thus severing trade entirely. No raiding income is gained from this, however.
Land trade routes are available when two factions border each other; the trade takes place along the roads passing through the regions. These roads may be raided by armies hostile to any faction using the road for trade.