Material

Material is a resource used to construct things in GambCiv.

Harvesting
You can cut down trees and harvest reeds to get 15 material per hex.

Most maps are covered in forested terrain. Also forests grow over time in GambCiv, so you will always have plenty of material.

Lumbermills
Lumbermills double the amount of material you get from harvesting nearby forests. Their range is limited to 3 hexes however, and once these forests are harvested, it's very expensive in action points to replant the same location.

For this reason, some players find lumbermills to be a waste of gold.

General construction
All buildings and structures in GambCiv require material to create.

Naval warfare
Ships require a lot of material to create. On large oceanic maps, you will need a steady source of material to fund late-game navies.

Mushroom farming
Material can be indirectly converted to gold by using it to farm mushrooms.

If there is enough cave terrain on the map, this can be combined with lumbermills to make even more gold per action point than using gold mines.