Resources

Civilization 4 has 35 resources in three groups: strategic resources that units and buildings need (copper, iron, horse, oil, aluminum, coal, uranium, plus stone and marble for wonders), health resources such as wheat, corn, rice and fish (+1 health each), and happiness resources such as gold, silk and wine (+1 happy each). A resource works once improved and connected by road, river or coast.

Civilization 4's resources come in three groups: strategic resources that some units and buildings require (copper, iron, horse, ivory, oil, aluminum, coal and uranium, with stone and marble speeding wonders), health resources (+1 health each in every connected city) and happiness resources (+1 happy face each). Firaxis counted 35 resources in the game on its 2005 feature comparison, and the base game's manual (pp. 112-122) lists each with the technology that reveals it, the improvement that works it and the yield it adds to its tile. A resource helps only after a Worker improves it and a road, river or coast connects it to your cities. Units that need resources are on Units; the improvements themselves are on Terrain and Improvements.

3D map of a city of brick buildings on a shore with a red and white lighthouse and piers, two sailing ships and a galley offshore, and silos, fields and a windmill on the green land around it. — Gameplay from the Steam store page: a coastal city labeled Yayoi, building a Colosseum, with a lighthouse, docks, sailing ships, farms and silos around it. Firaxis Games and 2K

Quick facts

Resources	35, by Firaxis's count
Groups	Strategic, health, happiness (the city screen's Resource Box)
Hidden until a tech	Copper (Bronze Working), Iron (Iron Working), Coal (Steam Power), Oil (Scientific Method), Aluminum (Industrialism), Uranium (Physics)
Health resources	Banana (+2), clam, corn, cow, crab, deer, fish, pig, rice, wheat (+1 each)
Happiness resources	Dye, fur, gems, gold, incense, ivory, sheep, silk, silver, spices, sugar, whale, wine, and Hit Movies, Musicals and Singles
Wonder speed	Stone, marble, copper, iron, aluminum and uranium each halve the build time of certain wonders
Connection	Improved inside a city's radius, or joined by road, rail, river or coast
Trading	Annual deal of at least 10 turns; the capital must be connected

Source: Civilization IV manual, pp. 31, 102, 112-122, 150; civiv.com compare features (archived).

How resources work

A resource gives its benefits only when it is improved and reachable. The base manual (pp. 72, 150) says a city gets an improved resource inside its own radius "roads or no roads", while other cities need it joined to them by road, railroad, river or coastline; a resource must also be inside your borders. The city screen's Resource Box sorts what a city has into strategic, health and happiness columns, with a number beside any resource you have more than one of.

Each resource also adds yield to the tile it sits on. Improving it raises that yield: wheat gives +1 food unimproved and +2 food under a farm, and gold gives +1 commerce unimproved and +1 production and +6 commerce under a mine, per the base manual (pp. 115, 122). Soren Johnson, the lead designer, built city sites around this: his afterword (p. 178) gives a farm on wheat (+4 food in his example, against +1 for the farm and the wheat alone) as what gives each city its role.

Firaxis also spread the key resources out. Johnson wrote in Game Developer in 2010 that Civ 4 never placed two Iron sources within seven tiles of each other, to limit bad luck from the map.

Strategic resources

Strategic resources unlock units, and some unlock or speed buildings. The base manual (pp. 112-122) lists what needs each:

Resource	Revealed by	Improvement	Improved yield	Needed for
Copper	Bronze Working	Mine	+3 production	Axeman, Spearman, Maceman, Phalanx (each or iron); halves the Colossus, Statue of Liberty, Internet
Iron	Iron Working	Mine	+3 production	Swordsman, Pikeman, Crossbowman, Cannon, Frigate; Knight and Conquistador (with horse); Ironclad (with coal); halves the Eiffel Tower
Horse	Always visible	Pasture	+2 production, +1 commerce	Chariot, Horse Archer, Knight, Cavalry and their unique versions
Ivory	Always visible	Camp	+1 production, +1 commerce	War Elephant; +1 happy
Stone	Always visible	Quarry	+2 production	Halves the Pyramids, Stonehenge, Hanging Gardens, Chichen Itza, Kremlin, Notre Dame and others
Marble	Always visible	Quarry	+1 production, +2 commerce	Halves the Oracle, Great Library, Parthenon, Taj Mahal, Versailles and others
Coal	Steam Power	Mine	+3 production	Railroad; Ironclad
Oil	Scientific Method (worked with Combustion)	Oil well, offshore platform	+2 production, +1 commerce	Tank, Panzer, Fighter, Bomber, Gunship and most modern ships
Aluminum	Industrialism	Mine	+3 production, +1 commerce	Jet Fighter, Modern Armor, Stealth Bomber (each with oil); halves the Apollo Program, Space Elevator, SDI
Uranium	Physics	Mine	+3 commerce	Nukes, ICBM; ships as an alternative to oil; halves the Manhattan Project

Source: Civilization IV manual, pp. 112-122.

Copper and iron are interchangeable for the early melee units, which is why both are worth claiming. A unit that needs "X and Y" needs both resources connected; one that needs "X or Y" needs either.

Health resources

Each health resource gives +1 health in every city it reaches (banana gives +2), and buildings add +1 more from certain ones. The yields are from the base manual (pp. 112-122); the building bonuses from the Warlords manual's building chart:

Resource	Tech to work	Improvement	Improved yield	Extra health from
Wheat	Agriculture	Farm	+2 food	Granary
Corn	Agriculture	Farm	+2 food	Granary
Rice	Agriculture	Farm	+1 food	Granary
Fish	Fishing	Fishing boats	+3 food	Harbor
Clam	Fishing	Fishing boats	+2 food	Harbor
Crab	Fishing	Fishing boats	+2 food	Harbor
Pig	Animal Husbandry	Pasture	+3 food	Supermarket
Cow	Animal Husbandry	Pasture	+1 food, +2 production	Supermarket
Deer	Hunting	Camp	+2 food	Supermarket
Banana	Calendar	Plantation	+2 food (+2 health)	Grocer

Source: Civilization IV manual, pp. 112-122; Warlords manual, charts pp. 129-134.

Health matters because each unhealthy face over a city's health costs 1 food, so food resources pay twice: once on their own tile and again in every connected city's health. See Cities for the health rules.

Happiness resources

Each happiness resource gives +1 happy face in every city it reaches, and several buildings add +1 more from certain ones (per the Warlords manual's building chart, the Forge from gems, gold and silver, the Market from fur, ivory, silk and whale, the "Theatre" from dye, and the religions' cathedrals from incense):

Resource	Tech to work	Improvement	Improved yield
Gold	Mining	Mine	+1 production, +6 commerce
Gems	Mining	Mine	+1 production, +5 commerce
Silver	Mining	Mine	+1 production, +4 commerce
Incense	Calendar	Plantation	+5 commerce
Dye	Calendar	Plantation	+4 commerce
Silk	Calendar	Plantation	+3 commerce
Spices	Calendar	Plantation	+1 food, +2 commerce
Sugar	Calendar	Plantation	+1 food, +1 commerce
Fur	Hunting	Camp	+3 commerce
Ivory	Hunting	Camp	+1 production, +1 commerce
Sheep	Animal Husbandry	Pasture	+2 food, +1 commerce
Whale	Optics	Whaling boats	+1 production, +2 commerce
Wine	Meditation (base manual)	Winery	+1 food, +2 commerce
Hit Movies, Hit Musicals, Hit Singles	Hollywood, Broadway, Rock 'n Roll wonders	none	+1 happy each, no yield

Source: Civilization IV manual, pp. 112-122. The manual lists incense under Mining and a mine in one place and under a plantation in another; GameSpot's walkthrough gives Plantation (Calendar). GameSpot's technology table also puts the winery under Monarchy rather than Meditation.

The three "hit" resources are made by wonders, not found on the map: each wonder gives its owner five of them to use or trade, per the Warlords manual's wonder chart.

Trading resources

Resources are traded as "annual" items, swapped only for other annual items such as gold per turn or Open Borders, and a deal runs at least 10 turns, per the base manual (pp. 102-104). The giver loses the resource's benefits for the length of the deal unless it has a second source; the receiver gets all of them, including the right to build the units it allows. Both sides' capitals must be connected to their trade networks, and a traded resource reaches only cities connected to the receiver's capital. Spare copies of a luxury are the usual currency of these deals; see Diplomacy.

Corporations and resources (Beyond the Sword)

In Beyond the Sword, corporations consume resources to produce their bonuses. Each corporation's benefit scales with how many of its resources a city has: Cereal Mills, for example, uses wheat, corn or rice and gives +0.75 food per resource, and Standard Ethanol turns corn, sugar or rice into oil, per the Beyond the Sword manual (pp. 21-22). Aluminum Co. likewise produces aluminum from coal. The seven corporations are on Corporations.

Frequently asked questions

How many resources are in Civ 4? Civilization 4 has 35 resources by Firaxis's own count on its 2005 comparison page, including the three made by wonders (Hit Movies, Hit Musicals and Hit Singles). They fall into strategic, health and happiness groups.

Where is copper or iron in Civ 4? Civilization 4 hides copper until you learn Bronze Working and iron until Iron Working, per the base manual; both are worked with a mine. Either one lets you build Axemen, Spearmen and Macemen; Swordsmen and Pikemen need iron.

What does oil do in Civ 4? Oil in Civilization 4 is revealed by Scientific Method and worked with Combustion through an oil well or offshore platform; it is required for tanks, aircraft and most modern ships, per the base manual. In Beyond the Sword the Standard Ethanol corporation can also produce it.

What resources give health in Civ 4? In Civilization 4, wheat, corn, rice, fish, clam, crab, pig, cow and deer each give +1 health to connected cities, and banana gives +2, per the base manual. Granaries, Harbors, Grocers and Supermarkets add +1 more from some of them.

What are luxury resources in Civ 4? Civilization 4's happiness resources are dye, fur, gems, gold, incense, ivory, sheep, silk, silver, spices, sugar, whale and wine, each +1 happy face in connected cities, plus the wonder-made Hit Movies, Musicals and Singles, per the base manual.

What do stone and marble do in Civ 4? In Civilization 4, stone and marble halve the build time of certain wonders, stone for the Pyramids and Stonehenge among others and marble for the Oracle and Great Library among others, per the base manual. Both are worked with a quarry after Masonry.

Why can't I use my resource in Civ 4? A Civilization 4 resource works only when it is improved with the right improvement, inside your borders, and connected to the city by road, rail, river or coast. To trade it, it must also connect to your capital, per the base manual.

Sources

Sid Meier's Civilization IV manual (with Soren Johnson's "Afterwords"), 2K Games and Firaxis Games, 2005, read Oct 21, 2026
Civilization IV: Warlords manual, 2K Games and Firaxis Games, 2006, read Oct 21, 2026
Civilization IV: Beyond the Sword manual, 2K Games and Firaxis Games, 2007, read Oct 21, 2026
Civilization IV compare features, 2K Games and Firaxis Games (civiv.com, archived), 2005, read Oct 21, 2026
Civilization IV Walkthrough, GameSpot (Doug Radcliffe), Jan 18, 2006, read Oct 21, 2026
Analysis: Soren Johnson On Playing The Odds, Game Developer, Mar 16, 2010, read Oct 21, 2026