Firewood is made by cutting up tree trunks or logs into blocks of wood and finally into firewood, preferably with a splitting axe. Each block of wood gives between 20 and 25 units of firewood. To light a fire on an open tile, there must be at least 2 pieces of firewood on the ground. When lighting a fire in a fireplace, there must be at least 4 pieces of firewood in the fireplace. Burning firewood is the most economical way of using wood for fires.

Fires can spread to adjacent tiles that have firewood on them. This tendency can be exploited to prepare many fields for farming, but can also potentially burn down a player's cabin.

Firewood can be carved.