Terrain

Terrain tiles are all tiles that do not contain a building. There are nine different kinds of terrain tiles: Forest, Grass, Dirt, Desert, Rubble, Trenches, Ridge, Mountain, and Water. A quick visual guide to terrain can be found at the bottom of this page.

Units can move through all tiles except for water, mountain and ridge tiles. Zeppelins can pass through any tile.

Terrain tiles can be divided into two categories: Indestructible tiles and destructible tiles. Destructible tiles can be changed by building on them, or they can change automatically due to changes in humidity.

Destructible tiles
Forest, grass and dirt are the only terrain tiles that can be destroyed once created. At the end of the game, grass and forest tiles add 1 point to the final score, whereas dirt tiles do not.
 * Forest tiles are grass tiles that contain at least 1 tree. They have a 25% chance of being created from a grass tile every spring. Trees count as bodies in combat, protecting units on the tile. Once all trees are destroyed, a forest tile turns into a grass tile. Forest tiles also offer some protection to firestorm.
 * Grass tiles are created from forest tiles that lose all their trees. Grass tiles turn into dirt tiles when they are destroyed in combat, or they can revert back to forest tiles in spring.
 * Dirt tiles are created from destroyed grass tiles. Once the humidity of a dirt tile drops to 0, it turns into a desert tile.

Indestructible tiles
Desert, rubble, trenches, ridges, mountains and water are impossible to destroy. Despite mountains and ridges having hit points (each peak on the tile counts as a separate body), they are indestructible.
 * Desert is created if grass, dirt, soil or crops tiles reach 0 humidity.
 * Rubble is created if any building tile gets destroyed.
 * Trenches can be created by riflemen on forest, grass, soil, crops or dirt tiles.
 * Ridges, mountains and water tiles are permanent tiles on the map and cannot be altered.