Advance
Efficient Mining
We shall issue a decree to refine every aspect of metal mining within our domain, in an effort to regulate its presence in our markets.
Advance tree
It has no requires, so the game files don’t say where this goes. When the game builds the 
Discovery tree, it adds this at the end of a branch with room for it, in the same spot in every campaign.
Expand Mining Cost−10%
Iron Output+10%
Copper Output+10%
Belongs to 1
- DiscoveryAge
icon = efficient_mining
for = adm