Wood, stone, iron, and crop are necessary for upgrading buildings, training troops, and building walls. They can also be bought and sold in the Market. You will need to upgrade your Lumber Mill, Stone Mine, Iron Mine, and Cropland to increase resource production. Tap on each icon for details.
Crops feed your troops. If you have a large troop count, you need to watch your crop supply. If you don’t have enough crops, your troops will starve..