Resource (Civ4)

A resource is a special commodity which typically gives bonus production to its tile, and also gives bonuses to all cities which have access to it. A resource on the map is called a tile resource if the context is unclear. A resource that a civilization has access to is just called a "resource"; unfortunately, there is no widely used term to disambiguate this usage from "tile resource." For the purposes of the wiki, we refer to tradeable resources as trade resources.

Seeing Resources

Tile resources are shown on the main map using their own graphics. You can also turn on resource bubbles to more clearly locate them. Some tile resources will not be revealed on the map until particular technologies are known; for example, Horses are not revealed until a civilization knows the Animal Husbandry tech.

The trade resources that each particular City has access to are shown on the upper right portion of the city screen in iconic form, along with the effect that the resource has in that city. Strategic resources have no direct effect; some of them allow the building of particular military units, while others offer a production bonus to the construction of some buildings or wonders. Luxury and food resources will give one or two points of happiness or health.

Accessing Resources

There are several means to gain access to a trade resource. These are reviewed in this section.

Via Tile Development

The fundamental way one gets most trade resources is to "enable" the resource with an appropriate technology, and then to "unlock" a tile resource by building its particular tile improvement on it. (Alternatively, one may unlock any land-based resource either by building a Fort on it, or by settling a City directly on top of it; however, since they give no improvement bonus to the tile, it is typically preferable to build the proper tile improvement.) The tile improvement which unlocks each particular resource is listed in the tables below. For example, Wheat is unlocked by a Farm.

For the most part, the enabling technology is the technology which allows the building of the resource's particular tile improvement. For example, Gems are enabled by Mining, which is the technology which allows the building of the Mine; prior to the discovery of Mining, a City settled atop Gems will not have the Gems' +1 bonus, nor will Gems be made available for trade. The sole exception is Uranium which, despite being associated with the Mine improvement which is allowed with Mining, is only enabled by Fission.

In summary, to gain access to the trade resource in a city, all of the following conditions must hold:

• The resource must be revealed by the revealing technology.
• The civilization controlling the tile must have the technology to enable that resource.
• The tile must have the right tile improvement (or a Fort, or a City) to unlock the resource.
• The tile must have trade access to the city.

Unless directly settled upon by a City, to get trade access to a tile resource, its tile must be connected by road or river to a nearby city. When you build a road to a resource tile which you've improved, this is called hooking up that resource. To allow trade with an encountered foreign civilization, the network of roads and rivers must connect all of: 1. the tile resource, 2. your Capital city, and 3. the foreign civilization's Capital city.

Via Wonders

There are three late-game trade resources - Hit Movies (), Hit Singles (), and Hit Musicals () - which are created via building particular wonders. When a civilization owns such a wonder, it obtains a certain number of the associated hits into its trade network. (The particular number of resources varies with the map size—more resources for larger maps.) Hits cause happiness in any civ and may be traded just as any other trade resource.

Via Trade

Trade resources can also be gained by trading between civilizations. With trade access, one civ can make a deal with another to supply a trade resource, in return getting gold or some other trade resource.

Via a Corporation

There are two trade resources, Oil and Aluminum , which can alternatively be accessed in a city by having a corporate branch there. Oil is available in all cities with Standard Ethanol . Aluminum is available in all cities with Aluminum Co. .

Tables of Resources by Type

There are three main subtypes of resources: strategic resources, luxury resources, and food resources. These are described below, with a listing of the resources of each type.

Strategic Resources

With the exception of Uranium , all strategic resources give +1 Production tile bonus on their tile regardless of what tile improvement it may have, so long as the resource has been revealed. All except Uranium give additional hammers when unlocked by the proper tile improvement.

Most strategic resources allow the building of certain military units, for example, a city must have access to Horses to build mounted units, Iron for Swordsmen, or Uranium for the ICBM. Most of them also give a +100% production bonus to certain buildings. Marble and Stone are exceptional in that they do not permit any military unit, and one or the other of them gives +100% to the building of most wonders.

Resource, Tile bonus		Improvement (Requires)	Improvement base yield	Improvement bonus yield	Revealed by	Note
	Aluminum, +1	Mine (Mining)	• +2 • +1 with a railroad	+1 , +1	Industrialism	Also provided by
	Coal, +1	Mine (Mining)	• +2 • +1 with a railroad	+1	Steam Power	Allows building of railroads
	Copper, +1	Mine (Mining)	• +2 • +1 with a railroad	+1	Bronze Working
	Horse, +1	Pasture (Animal Husbandry)	none	+2 , +1	Animal Husbandry	+1 with Hippodrome (Byzantium only)
	Iron, +1	Mine (Mining)	• +2 • +1 with a railroad	+1	Iron Working
	Marble, +1	Quarry (Masonry)	+1 with a railroad	+1 , +2	always revealed
	Oil, +1	Well (Combustion) or Offshore Platform (Plastics)	none	+2 , +1	Scientific Method	• Allows building of railroads • Also provided by
	Stone, +1	Quarry (Masonry)	+1 with a railroad	+2	always revealed
	Uranium	Mine (Mining)	• +2 • +1 with a railroad	+3	Physics	• Enabled by Fission • No tile bonus

Luxury Resources

Most tile-based luxury resources give +1 Commerce tile bonus on their tile regardless of what tile improvement it may have. The three exceptions are Ivory , which has a tile bonus of +1 Production, and Sugar and Whale , which both have a tile bonus of +1 Food.

All tile-based luxury resources give additional Commerce when unlocked by the proper tile improvement. Note that Gems , Gold , and Silver have a -1 improvement bonus yield, which decreases the Mine's Production from +2 (without a railroad) to +1 .

All luxury resources give +1 Happiness to cities that have access to them. Many give an additional +1 Happiness with an appropriate building, whereas others give +1 Health.

Resource, Tile bonus		Improvement (Requires)	Improvement base yield	Improvement bonus yield	Effects	Note
	Dye, +1	Plantation (Calendar)	none	+4	• +1 • +1 with Theatre
	Fur, +1	Camp (Hunting)	none	+3	• +1 • +1 with Market	Obsoleted by Plastics
	Gems, +1	Mine (Mining)	• +2 • +1 with a railroad	-1 , +5	• +1 • +1 with Forge
	Gold, +1	Mine (Mining)	• +2 • +1 with a railroad	-1 , +6	• +1 • +1 with Forge
	Incense, +1	Plantation (Calendar)	none	+5	• +1 • +1 with Cathedral
	Ivory, +1	Camp (Hunting)	none	+1 , +1	• +1 • +1 with Market	Obsoleted by Industrialism
	Silk, +1	Plantation (Calendar)	none	+3	• +1 • +1 with Market
	Silver, +1	Mine (Mining)	• +2 • +1 with a railroad	-1 , +4	• +1 • +1 with Forge
	Spices, +1	Plantation (Calendar)	none	+1 , +2	• +1 • +1 with Grocer
	Sugar, +1	Plantation (Calendar)	none	+1 , +1	• +1 • +1 with Grocer
	Whale, +1	Whaling Boats (Optics)	none	+1 , +2	• +1 • +1 with Market	Obsoleted by Combustion
	Wine, +1	Winery (Monarchy)	none	+1 , +2	• +1 • +1 with Grocer

The three "Hit" luxury resources are exceptional in that they are not located on tiles. Instead, a monopoly is granted to whomever controls the resource's late-game wonder, either by building the wonder or by capturing it from another civilization.

"Hit" resource		Wonder (Requires)	Effects	Effects (Building bonus)	Effects (Unique building bonus)
	Hit Movies	Hollywood (Mass Media)	+1	+1 with Broadcast Tower	+1 with Mall (America only)
	Hit Musicals	Broadway (Electricity)	+1	+1 with Broadcast Tower	+1 with Mall (America only)
	Hit Singles	Rock 'n' Roll (Radio)	+1	+1 with Broadcast Tower	• +1 with Odeon (Greece only) • +1 with Mall (America only)

Food Resources

All food resources give +1 Food tile bonus on their tile regardless of what tile improvement it may have. All of them give additional food when unlocked by the proper tile improvement.

All food resources give +1 Health to cities that have access to them, and an additional +1 Health with an appropriate building.

Resource, Tile bonus		Improvement (Requires)	Improvement base yield	Improvement bonus yield	Effects
	Banana, +1	Plantation (Calendar)	none	+2	• +1 • +1 with Grocer
	Clam, +1	Fishing Boats (Fishing)	none	+2	• +1 • +1 with Harbor
	Corn, +1	Farm (Agriculture)	• +1 with irrigation • +1 with Biology	+2	• +1 • +1 with Granary
	Cow, +1	Pasture (Animal Husbandry)	none	+1 , +2	• +1 • +1 with Supermarket
	Crab, +1	Fishing Boats (Fishing)	none	+2	• +1 • +1 with Harbor
	Deer, +1	Camp (Hunting)	none	+2	• +1 • +1 with Supermarket
	Fish, +1	Fishing Boats (Fishing)	none	+3	• +1 • +1 with Harbor
	Pig, +1	Pasture (Animal Husbandry)	none	+3	• +1 • +1 with Supermarket
	Rice, +1	Farm (Agriculture)	• +1 with irrigation • +1 with Biology	+1	• +1 • +1 with Granary
	Sheep, +1	Pasture (Animal Husbandry)	none	+2 , +1	• +1 • +1 with Supermarket
	Wheat, +1	Farm (Agriculture)	• +1 with irrigation • +1 with Biology	+2	• +1 • +1 with Granary

Calculating Tile Yields

By using the above tables, along with the yield data from Terrain, the tile yields of any given tile can be calculated. Below are some examples of how such yields are derived.

Example 1

In this first example, a riverside Plains-Hill Windmill on top of Coal has a total yield of:

1 , 5 , 2

The adjacent city contains a Levee. The Windmill is only partly upgraded: the technology Replaceable Parts has been discovered, the technology Electricity has not been discovered, and the Environmentalism civic is not being run. The leader is not Financial.

Using the above tables, we see that Coal is unlocked by either a Mine (or a Fort, or a City) and only a Mine can allow Coal's improvement bonus yield of +1 . As a Windmill is being used instead, no improvement bonus yield is awarded. Additionally, even if the tile were connected to the civilization's capital by a road, the use of a Windmill means that the tile does not make available any Coal resource, neither for domestic use nor for foreign trade. Nonetheless, the tile may still be valuable to the adjacent city working it, due to the relatively high yield.

Category of Contribution	Yield Contribution
Terrain	Plains	+1	+1	0
"	Hill	-1	+1	0
"	No Terrain feature	0	0	0
"	Adjacent river	0	0	+1
Resource	Coal tile bonus	0	+1	0
Improvement	Windmill base yield	+1	0	+1
"	Replaceable Parts	0	+1	0
"	No Electricity	0	0	0
"	No Environmentalism	0	0	0
Improvement Bonus from Resource	No Mine Bonus from Coal	0	0	0
Buildings	River tile with Levee	0	+1	0
Total Yield on Tile	.................................	1	5	2

Example 2

In this example, a non-Financial leader has a Grassland-Flatland Mine on top of Gems, with no railroad, has a total yield of:

2 , 1 , 6

Using the above tables, we see that Gems are unlocked by either a Mine (or a Fort, or a City) with only a Mine allowing for the Gems' improvement bonus yield of +1 . Because a Mine is present, an improvement bonus of -1 +5 is awarded, which dramatically increases the tile's Commerce yield at the expense of a slight reduction of the Production yield which Mines usually provide. Because the enabling Mining technology has been discovered, the unlocking Mine improvement is present, and the tile is connected to the civilization's capital city by road network, the Gems resource is made available to the civilization for domestic use or trade. If not traded away, the Gems provide +1 to all connected cities and an additional +1 to those with a Forge, with additional bonuses available to connected cities with Civilized Jewelers Inc. .

Category of contribution	Yield Contribution
Terrain	Grassland	+2	0	0
"	Flatland	0	0	0
"	No Terrain feature	0	0	0
"	No river	0	0	0
Resource	Gems tile bonus	0	0	+1
Improvement	Mine base yield	0	+2	0
"	No railroad	0	0	0
Improvement Bonus from Resource	Mine Bonus from Gems	0	-1	+5
Buildings	None
Total Yield on Tile	.....................................	2	1	6

See also

• Resource in other games