Developing a city is a key factor to succeed in the world of Arcadia. A developed city brings more resource production, more people can be recruited in armies and more advanced units become available for training.
A full buildings list tech tree can be found here.
There are six main resource production buildings:
There are also two special production buildings that are available only if the city is near a Diamond or Palladium mine:
Lumber, Stone and Iron are used mostly for buildings and the upkeep cost to maitain them, so it's important to develop those buildings at the start to maintain a strong flow of resources to keep your city expanding.
A steady flow of Food is essential for the development of a city to prevent starvation. The more people in the city, the more Food is needed to feed them. Food is also used to feed armies and fleets. Always check that you have enough food production to satisfy your city needs, you can check the food production and consumption in the Main tab.
Horses are used to mount units on them creating cavalry type ground units.
Palladium is used to train Silver Knights, the most formidable sword based ground unit, while Diamond is used to train Mages and capture dragons.
In order for your city to grow and be able to house more people Urban Development must be built and upgraded as soon as the city reaches its population limit.
The City Hall is the main requisite for upgrading other buildings.
The Academy, Blacksmith and Militia Headquartes are built to gain access to new technology that allows the construction of new buildings and training of new types of ground units.
The Market allows the trading of resources with the local market. Also you can place buy orders and sell orders to trade with other players. The bigger the market, the more mercenaries come to the city and can be hired.
The Storage is a low cost building that increases the storage space for resources. It's a good practice to have Storage upgraded as soon as possible to not lose any resources in case you reach the storage limit of that resource.
The Church of the Light provides increased population growth. It's essential to speed up the development of a city.
Walls are needed for the defense of the city, the bigger the walls are the more time an enemy sieging a city must wait before he can attack. Also during an attack it gives time for your archers to fire on the enemy. The archers will fire until the enemy manages to destroy the walls with artillery.
The Castle and the Shipyard allow the training of ground units and the construction of ships. Upgrading those buildings will give access to new types of units and more training slots.
The Swordmasters Guild, Archery Grounds and Siege Works allow the training of more advanced ground units. While the Arcane Guild allows the training of Mages.