Gold is a resource used to pay for things in GambCiv.
How to getEdit
In the early stages of a match you will farm tobacco to gain more gold. Each one harvested gives you 11 gold.
You should also harvest any nearby mushrooms for free gold. You get 25 gold from each mushroom.
Just like in normal Wesnoth, you will get some income from village-based terrain. Given how expensive most buildings are, this is probably not the best method of gold collection.
The other players might give you gold via your trading posts.