This guide is part of the official guides released by Empires and Allies. There are four resources in Empires & Allies: Coins, Wood, Oil, and Ore. How much of each a player has is displayed at the top of the screen:
Coins are the most important resource in Empires & Allies. You can Coins to buy anything that does not cost Empire Points to purchase. You can earn Coins during combat, from Farms and Houses, through Daily Bonuses, and from performing tasks for your Friends.
Wood allows you to build all buildings and decorations. You can obtain wood for your Empire by clearing trees on your island (10 Wood for trees and 1 Wood for bushes), through the Gifting Menu, or purchased through a friend’s Market.
You can generate Wood from a Lumbermill with Coins. There are three types of Lumbermills. More advanced versions are unlocked by increasing your Empire’s population and producing more Wood.
Oil allows you to build all Advanced Ground, Air, and Navy Units. Oil is produced by Oil Wells, which have contracts bought with Coins. There are three types of Oil Wells that you can unlock by increasing your Empire’s population. More advanced Oil Wells produce more Oil. Oil can also be bought and sold on the Market.
Ore allows you to build advanced Buildings and Units of all types. Ore comes in one of five types: Aluminum, Iron, Copper, Gold, and Uranium. Your Empire can mine one type of Ore, which is chosen randomly when you first create your Empire. Your Empire’s Ore is produced by Ore Mines. More advanced Ore Mines can be unlocked by increasing your Empire’s population and producing more Ore.
There are Buildings and Units which require other types of Ore that your Empire does not produce. There are a few ways to get Ore that you do not produce.
- You can get them from Critical Hit or Critical Kill combat drops.
- At the end of combat, you receive Ore as part of the victory reward.
- You can request your Friends to send you Ore through the Friends Ladder.
- You can use the Market to buy and sell Ore.
Source: Zynga Forums