Rise of Nations/Resources

There are several main resources in Rise of Nations, as described below

The Uses
Food is one of the most common resources, and is needed in large quantities to raise armies of the basic infantry unit (such as the musketeer or slinger, for instance) or other basic units (such as the light cavalry). Food is the only resource required for creating villagers, who's resource increase tree starts at approximatley 25 food and rises to over 50. Food is used extensivley in the early game, although its usefulness declines later on, when it is pushed out by Oil, Metal, and Wealth.

Gathering
Food can be gathered by farms, which are limited to five per city (seven for the Egyptians), and give a base 10 gather. Fishing ships can also gather food. Fishing ships are very useful in water maps, serving both as a farm and as a sea-based lookout. Food production from farms is increased by building a granary in the city in which the farm is placed. Furthur upgrades can be bought at the granary. Food can also be gathered from a number of rare resources.

The Uses
Timber is one of the best resources to have on hand in large quantities, as it is used in almost all buildings and basic infantry units. Timber is used in all ships pre-industrial age, and most buildings even after the 20th century dawns. Wood is used to build farms, making it a nescessity for quick expansion.

Gathering
Also referred to as "wood", timber is gathered most easily from woodcutter's camps built within a city limit, such that a lumbermill is boosting production. Woodcutter's camps hold anywhere from two to ten workers/villagers, based on the number of trees in the camp's range. Lumbermills have several upgrades for wood production, along with a few to strengthen buildings. Timber is found in only a few rare resources, and therfore large amounts of manpower must be dedicated to its production.

The Uses
Metal is used more late-game, especially after the dawning of the 20th century in the Industrial age in the form of ships and airplanes. Metal is also used in heavy infantry and cavalry, and all artillery post gunpowder age. One of the most important resources, it is furthermore used in machine guns, anti-aircraft buildings and vehicals, tanks, scout cars, flame-throwers, bomber, fighter, and fighter-bomber aircraft, buildings not withstanding. Many computer AI scripts will also request large sums of metal, up to 5000, as tribute in exchange for an alliance, especially in the early game before many players will have built smelters.

Gathering
Metal is gathered from mines, which are positioned near mountains. The size of the mountan determines the number of workers that can be stationed at the mine at any one time. Smelters can also boost metal production up to three times, assuming the mine in question is within the ecenomic radius of the same city as the smelter. Many rare resources also have a metal bonus, including whales.

The Uses
Oil is most definatley the most important resource in the late game, especially after the advent of aircraft carriers in the modern age. Oil is required in extremely large quantities for both conventional and nuclear missiles, making non-cheat nuclear warfare a very costly business. Oil is used in all mechanized cavalry and artillery from the industrial age on, along with airplanes and anti-aircraft guns. Oil is very important for most every army, as it is used in many units and, when required, is generally required in large quantities.

Gathering
Oil is gathered from oil wells, which each produce 35 oil every thirty seconds by default and take one citizen to run. Oil wells are found in the rocky areas that are abundant on most of the maps, and in sea-based depostis denoted by a large black square under the surface. When a worker is assigned to build an oil well at sea, (an "oil rig") the worker simply moves out to the position in a boat and builds the well, which can then be used as a sea-based lookout. Oil rigs are poplar targets for marauding enemy fleets, though, so sea based exploration can be a costly business. Oil refineries, which serve the same purpose as a granary or lumbermill for food and timber, have the distinct advantage of being able to be built anywhere and have a stackable +33% effect. Therfore, if someone built two refineries, all of his oil wells would have a +66% bonus in production. Oil has the distinct stress-saving feature of having the screen jump to the nearest source when a citizen is told to build a well.

The Uses
Almost everything requires wealth, to put it simply. Most reasearch and many units require it, along with many buildings.

Gathering
Wealth can be gathered from caravans, markets, or rare resources (such as whales). The Taxation technology at the temple provides a wealth gather rate based on the percentage of world territory controlled by your army. The percentage of taxation can be upgraded by various temple technologies. Caravns commute constantly between two cities, gathering wealth along the way through trading.

The Uses
Research, plain and simple. Knowledge is not required for anything else other than reasearch.

Gathering
Since knowledge is the only resource that cannot be traded, knowledge must be gathered by scholars at universities. Each university can hold seven scholars, whose gather rate can be upgraded by various university technologies. Scholars are usually killed off after all of the research is complete in a game, since the resource they gather is then unnecessary and they serve no other purpose.