Oil does not show up until the Industrial Age, when the use of the internal combustion engine becomes prevalent. Oil essentially replaces Food as a staple resource in the late-game, as it is needed for some modern buildings and units such as aircraft, vehicles, modern ships and missiles, as well as their upgrades.
Oil is gathered by building an Oil Well over a patch of oil and having a Citizen operate the structure. Oil can also be gathered from the sea by sending a Citizen out to build an Oil Platform on the oil patch. Upon completion of either structure the nation is granted a one-time bonus of 50 Oil. Both Oil Wells and Oil Platforms then gather Oil at a rate of 35 (per 30 seconds).
The global gather rate of Oil can be increased by building Refineries, with each Refinery adding 33% to the base gather rate of Oil. A nation needs to develop Science 6 (Electronics) to be allowed to build Refineries. Building a Refinery in every city may allow a nation with a relatively small number of Oil Wells to still compete effectively.
Adopting Capitalism grants a nation a one-time bonus of 500 Oil, as well as increasing the gather rate by +100 Oil (per 30 seconds).
The gather rate of rare resources in friendly (i.e. own and allied) territory can be increased by researching the Taxation line at the Temple (+20%, +50%, +100%, +200%) and by building the Porcelain Tower (+200%).
- The Russian Power of the Motherland: +20% bonus Oil production.
- The Eiffel Tower increases the base gather rate of Oil by 100% and the Commerce Limit for Oil by 200.
- The Kremlin increases the Commerce Limit for Oil by 200.
- Whenever possible, be sure to be the first to seize any available oil resource as you will not be the only nation competing for natural resources. This is important, especially when computer-controlled nations will follow this tactic frequently. Be quick to find and construct an Oil Well; otherwise, you may struggle to construct military units.
- If you are unable to achieve the previous tactic, it is possible to build Refineries in every city to increase oil production.
- In the Scenario Editor, to place oil, you must place a patch of rocks then click on the rock patch again with the rock-placing tool.
- There is a glitch when placing an oil patch in the water. When this happens, the oil patch in the water will appear like the one on the land instead of the water.