Trade guide

An introduction to trade in M&T 3.0
Trade in EU4 has always been a very abstract affair. “Trade Value” would shift between “Trade Nodes” that you could capture or steal through trade power from provinces, merchants or light ships. Capturing trade value from certain “trade goods” would gain you various bonuses. Steering trade from node to node would add a trade steering bonus to trade value. While engaging in its own right, it was hard to wrap your head around. No goods were actually traded because there was no demand to be met. Instead trade was about claiming leftover production value that leaked into the wide world.

M&T 3.0 tries to simulate actual trading. Now that every province has a population, those pops are set to work in properties that produce various trade goods like food, raw materials or luxuries. Some of these trade goods are needed to keep your pops alive or make them more happy while others are needed to maintain various structures within the realm. Because every province produces different goods in different quantities, while also having different demands to be met, trade is necessary to distribute the goods from places with surplus to areas in need.

The trade system in short
Every game year on the second of January trade in the world is conducted. Provinces provide a supply and demand of goods which is gathered up in a sector: a grouping of all provinces of the same nation within a particular trade node. Sectors get assigned a sector score determined by, among others, the number of merchants controlled by its nation, trade power in the sector and trade ideas.

The sector with the highest sector score gets to trade first with sectors in the trade nodes it has access to. It will prioritise filling the demand and selling the surplus of their provinces, then fill the stockpile and finally look for profitable trades outside their own borders. This is limited by the amount of commerce produced by the provinces within the sector. Sectors will try to buy for the lowest price they can find and sell at the highest; the difference is added to commerce profits.

Once the sector with the highest sector score has exhausted its supply of commerce the sector with the second highest sector score gets its turn, going down the list until everyone is done. The goods are then distributed to the provinces and the stockpile, while surplus production that couldn’t be sold is added to the stockpile or otherwise destroyed, and unfilled demand becomes a shortage. Finally, prices of goods in the sectors are adjusted based on supply and demand and trade value is generated from the amount of trade done.

Vanilla trade
The original trade system of vanilla EU4 is still in the game though slightly altered. It now exclusively simulates the taxing of trade value which is solely determined by the volume of trade being done in the province. Compared with vanilla this trade taxing is a lot less lucrative. Trade efficiency is much harder to acquire and the trade steering bonus is removed: this was done to limit money magically appearing into the system from these sources. Trade power is also harder to come by as light ships are more expensive and provinces only generate any according to how much commerce they produce.