Each game account is allotted 2 (up to 10 if purchased) building slots, called lots, per server.

Warehouses, the prerequisite for any structure construction don't consume any lots.

Players are allowed to build a variety of structures if the requirements for their construction are met, which vary from port resources, player reputation with specific nation, level requirements and career requirements.

Also important to realize is that, different size structures need larger numbers of lots to be constructed. A Large Shipyard for example requires 3 lots, whereas a simple Iron Mine requires 1 lot.

These simple rules ensure that no one player can complete a production chain of any advanced game product without trading or interacting with other players. Some have claimed this to be a shortcoming of the game, although the majority of players agree that this is a refreshing idea which will give a nice edge to the in-game market.