City competitions happen near the beginning of day 5 and day 12 of each era, starting in era 2. Each competition lasts two hours, during which required goods must be transported to the city. In each city competition, five cities compete against eachother.
The goal of the city competition is to have a balanced delivery of the currently required goods during the competition: What counts is how much has been delivered of the weakest/lowest of the four goods after two hours. The city that has the highest delivery of its weakest good, is the winner.
During a city competition, you can see the delivery status off all four required goods by first placing your mouse over the competition symbol, and then moving it to the city name.
The winning city gets a 2x bonus on all city deliveries for 24 hours, starting at the moment where the competition ends. The runner-up gets a 1.5x bonus, and so on, as listed below.
If a city levels up during a city competition, the new good will continue the count of the old good. E.g. if 15,000 tonnes of iron had been delivered before the level up, and iron is replaced by leather for the next level, the 15,000 tonnes will be added to the amount of leather that is delivered during the remainder of the competition.
Levelling up during a city competition can be risky. If some players aren't online, they can't redirect their trains to the new good, and their deliveries of the good that is no longer required, don't help. Additionally, the new good may need to delivered from an industry that has a low level, and therefore low production capacity. On the other hand, you'll often have the benefit of delivering from an industry with low utilisation rate, and initial low waiting times.
In other words (the in-game description)Edit
From era 2, weekly city competitions take place between five cities at a time. Here, as many required goods as possible have to be delivered to the city in two hours. All players that are connected to the city automatically take part. From the start, all deliveries of the required city goods are counted for the competition.
At the end, the winner is the city to which the greatest amount of the least delivered good is delivered. It is therefore important to deliver the four goods in as balanced a way as possible. The intermediate results and the rewards for the individual positions can be seen by placing the cursor over the competition field on the left or on the map. Bear in mind that the stock of competition goods in the city is irrelevant for the competition.
If a city levels up during a competition and demands a new good, the new good assumes the delivered tons of the good which dropped out. If all four goods are exchanged, the new goods will be randomly assigned the delivery amounts of the goods which dropped out.