Each race gathers resources slightly differently, although they all must build workers with which to mine Gold and harvest Lumber. Some workers must gather and then return to their respective Town Hall buildings, while other races' workers use magic to move resources without needing to physically carry it back. All Gold and Lumber is taken to the appropriate building of each race. Human Peasants and Orc Peons can deliver Lumber to special mills, while Undead Ghouls can deliver wood to their Graveyards.

Once you have Gold and Lumber in your reserves, you can purchase units, construct buildings, or buy upgrades. You can also give resources to your allies in team games by clicking on the Allies Tab at the top of the screen.

Players start with 500 Gold and 150 Lumber.

The Orcs use a mining method very similar to the Humans.

The Night Elves must entangle the Gold Mine with their Tree of Life.

Once a Gold Mine has been haunted, the Undead can use Acolytes to worship the mine for Gold.

Gold
Mined from the rich earth of Azeroth and Lordaeron, this precious metal is commonly used in exchange for goods and services. As a rare substance that is always in short supply, Gold must be dug out from the rock and soil within the established Gold Mines. Many of these Mines were abandoned when the Orc raids began and the workers fled for their lives. Since the beginning of the War, these sites have frequently been operated while under the protection of military forces.
Gold is the main resource in Warcraft III. Gold is required to create new buildings, train units, and research upgrades. Gold is also required at Neutral Buildings to hire mercenaries, buy items, or activate special Neutral Building features. Players need to collect a steady stream of Gold to ensure their success. Whenever money is tight, expand to additional Gold Mines.

Gold is mined in different ways depending on the player's race. Humans and Orcs use work units to carry Gold from the Mine to their "Town Halls." The Night Elves' Tree of Life entangles the Gold Mine and drains the Gold out of a Mine with the use of Wisp workers. The Undead uses Acolytes to mine Gold. Five Acolytes surround a Gold Mine and extract Gold automatically using magic.

There is a "Gold tax" in place, known as Upkeep which is activated as players create more units. As players create more units, less Gold is recovered from the Gold Mine. Try to gain additional Gold by taking over additional Gold Mines to help balance this tax out.

Creeps or other players often guard Gold Mines. Players must decide whether risk of battle is worth the gain of the additional mine. If another player attacks while your forces are engaged or dying to Neutral Units, you may not have the forces to defend yourself. It's best to wait until you can afford to make an attack on multiple fronts. The decision is a gamble; it could pay off or it may cost you dearly.

When a mine you are using is low on Gold, you will receive an advisory warning that the Gold Mine is about to run out, and the minimap will ping the location of the mine. You will also receive a message when a Gold Mine is depleted. A mine is considered low on Gold at 1500.

Lumber
Lumber is harvested from the abundant forests that inhabit all but a few regions in the realm. The uses for Lumber are nearly infinite. Once a tree has been felled and returned to the community, it is processed and made ready for use as Lumber. Craftsmen then use this material to build many different structures as well as certain weapons and machines of war. Lumber may also be used in the research and construction of strange new devices or by those adept in the arcane arts to aid them in their magical studies.

Sharing Resources
Players in Multiplayer games can share resources with other players in the game via the Allies menu. Simply click on the resources next to the player's name to transfer resources to that player. A trading fee is charged with each transfer depending on the Upkeep of the player receiving the resources.
When an allied player leaves the game an indicator will pop up and will now appear in the top right of the screen indicating how much resources that player has. Make sure you give your allies all of your resources before leaving the game. You can transfer resources to dropped players' towns but you cannot make those dropped players towns transfer resources back to you.