A tile occupies a space on the map. A tile can have some number of buildings, trees or mountains on it, that can be lost when they take damage. When a tile loses all of its buildings or trees, it is destroyed and becomes a different type of tile.
Populated tiles have a certain amount of power, which is the number of buildings on the tile that have lights on. Power is spent when executing an order such as producing a unit. A tile may gain power at night based on its surroundings.
Some populated tiles can produce units. The size of the unit is determined by the power of the tile; the unit will consist of one figure for each powered building the tile has. Producing a unit lowers the power of the tile by the number of figures created.
The tile must have at least one power. When producing a ground unit (or an air unit), either the tile itself or the target tile must not be occupied by a ground unit (by an air unit, respectively). The owner must also have sufficient funds to produce the unit. If the tile fails to produce a unit for any of these reasons, the tile will try again in subsequent turns.
When producing a unit on an adjacent tile, the produced unit will be created on the producing tile itself and then move to the target tile if possible, bypassing any friendly units on the producing tile. The produced unit cannot attack when moving this way, but unless it is bypassing a friendly unit it may be subject to an attack of opportunity.
Some populated tiles can expand, transforming adjacent tiles into new populated tiles. Only Grass, Dirt, Forest, Soil and Crops tiles can be expanded upon. Expanding lowers the power of the tile by one.
The tile must have at least one power and the target tile cannot be occupied by a ground unit. The owner must also have sufficient funds to perform the expansion. If the expansion fails for any of these three reasons, the tile will try again in subsequent turns.
Some populated tiles can upgrade to become other populated tiles, such as towns into cities. Other tiles can upgrade themselves to increase their size, such as barracks or industry. Upgrading lowers the power of the tile by one.
The tile must have at least one power. The owner must also have sufficient funds to perform the upgrade. If the upgrade fails for either reason, the tile will try again in subsequent turns.
When the tile is upgraded this way, any Frostbite or Firestorm present on that tile is removed.
Some populated tiles can cultivate, transforming all surrounding tiles. Only Grass, Dirt, Forest, Soil and Crops tiles can be cultivated upon.
Tiles that are occupied by a ground unit or that are owned by the player that gave the order are not transformed.
The cultivating tile must have at least one power; if it does not have enough power, the tile will try again in subsequent turns. Some tiles will automatically cultivate when they are built.
All tiles can be given a Stop order. A tile given a stop order will not act on its own during its turn.
Stop orders may be useful if you wish to cancel a previously given order without giving it a new produce, expand, upgrade or cultivate order.
Populated tiles that are occupied by enemy units cannot execute any orders except Stop orders and do not gain power or generate income at night.