Terrain and Workers

3:16 Civilization 3's map is an isometric grid in which "each terrain square (also called a tile) is roughly diamond shaped", per the Complete manual (p. 7), and each square yields food, shields and commerce by its terrain type. Workers, the only units that can change terrain, raise those yields with irrigation, mines and roads, and later railroads, and they clean up the pollution that industry brings. Where a city stands decides which squares it can work, so terrain is the first thing to read on the map (see Cities and City Placement and Expansion).

Quick facts

Source: Civilization III Complete manual, pp. 7, 26, 58-60, 112-118, 212-213; Prima's Official Strategy Guide, pp. 21, 31.

Terrain yields

Every land and water square has a base yield of food, shields and commerce, a movement cost and a defense bonus for a unit standing in it. The table gives each terrain's base yield and what Workers can add. Coast, Sea and Ocean are the three water types that replaced the single Ocean of earlier games, per Prima's guide (p. 21).

Source: Civilization III manual (2001), pp. 206-207 and Prima's guide, p. 21 (Table 3-1); Marsh and Volcano from the Complete manual's terrain charts, pp. 212-213. Hills' "+2 shields" for a mine follows both manuals' charts.

15:07 Some Grassland squares carry a small rocky tuft and yield one shield on top of their food, per the Complete manual (p. 36). Special resources on a square add more again; they are on Resources and Trade.

Rivers, hills and disease

Rivers run along the edges of squares and give commerce and fresh water, according to the Complete manual (pp. 60, 83). A unit defending behind a river gets a bonus, rivers give no movement bonus, and they break the road bonus until Engineering. Hills and Mountains double a unit's sight range (p. 60), and their defense bonuses of +50% and +100% (p. 107) make them the places to hold; Combat has the full list of modifiers.

Flood Plains and Jungle carry disease. Cities near Flood Plains, and units and cities in Jungle, "risk death by disease", per the Complete manual (p. 87). Cities can be built on any square except water and Mountains (p. 36).

Worker jobs

Workers do every terrain job in Civilization 3, and only they can. Each job takes a number of turns that depends on the terrain, and Workers can redo a square as often as needed, per the Complete manual (p. 112). The base turns for each job are set in the editor's Worker Jobs section ("Turns to Complete"), per Prima's guide (p. 199); no source read for this page prints them.

Source: Civilization III Complete manual, pp. 59, 83, 113-118, 126-127; Play the World manual, pp. 22-23.

13:42 Roads matter beyond movement. A road cuts a square's movement cost to a third of a point and adds commerce, and an unbroken road links a resource to your cities, per the Complete manual (p. 116). Railroads cost nothing to cross and need both Iron and Coal as well as Steam Power (pp. 116-117), and once you have Steam Power your city squares become railroads automatically, per the 2001 manual (p. 69).

4:20 Workers can be put on automatic. The Automate order (A) has them improve land around your cities and build roads between them; narrower orders limit them to one city, to pollution, to clearing forests or to never replacing existing improvements, per the Complete manual (pp. 118-119).

Working faster

5:58 Several Workers on one square finish sooner: "two Workers work twice as rapidly as one, and three can accomplish a task in one-third the standard time", per the Complete manual (p. 112). Industrious civilizations' Workers "complete jobs faster" (p. 26), and the advance Replaceable Parts doubles every Worker's rate (p. 127). Government matters too: under Democracy Workers "work 50% faster than usual", and under Anarchy they "toil 50% slower", per the 2001 manual (pp. 127, 131); see Governments.

Clearing forests for shields

25:13 Clearing a forest gives the nearest city a one-time gift of shields. The Complete manual (p. 58) says only "a number of production shields"; Prima's guide (pp. 31, 43) gives 10 shields, adds that the forest need not be inside the city's radius, and notes that a cleared Forest usually becomes Plains, ready to irrigate. Prima calls it "just the ticket" for finishing a crucial unit or Wonder.

Soren Johnson, the game's co-designer, later called the trick "lumberjacking". In his Game Developer column of 2011 he wrote that because forests could be replanted, players repeated it on every tile, which he called "tedious and mind-numbing".

Captured Workers and slaves

Workers can be captured, and a captured Settler becomes two Workers. Any military unit can take a defenseless Settler, Worker or artillery piece with no defender nearby; the captive "retains its nationality" but works for its new owner, per the Complete manual (pp. 56-57). The 2001 manual adds that the old owner will often ask for its Workers back in trade talks (p. 132).

Some units turn beaten enemies into Workers. The Enslavement ability captures a defeated unit "and convert[s] it into a worker or other unit", and the Mayan Javelin Thrower, the English Man-o-War and the Privateer have it, per the Complete manual (p. 111). Unique Units has the rest of each civilization's special unit.

Pollution

Pollution appears around cities that make many shields or grow very large, and warning symbols on the city screen show the chance each turn, per the Complete manual (p. 88). The Complete manual says a polluted square's food, shields and commerce fall to zero until a Worker cleans it (Shift-C); Prima's guide (p. 53), written for the 2001 game, says output falls by 50 percent. The cures are the Mass Transit System (smog from population), the Recycling Center (pollution from industry) and clean power such as the Hoover Dam, which acts as a Hydro Plant for every city on its continent (Complete manual, p. 88).

Nuclear power adds a sharper risk. A Nuclear Plant in a city in civil disorder may melt down, killing half the city's population and polluting nearby squares, per the Complete manual (p. 89). Nuclear weapons pollute the squares around their target as well.

Global warming

Global warming in Civilization 3 depends on the whole world's population and pollution, not on polluted squares. Prima's guide (pp. 53-54) says the game weighs the total population of every city and the pollution points of every city's improvements and Wonders; the higher both are, the greater the chance. When it strikes, coastal land turns wetter (Plains and Grassland to Flood Plains and Jungle) and inland land turns to Desert. Every nuclear explosion raises the chance, and you cannot control rivals' pollution, only your own.

Conquests added natural damage as well. Volcanoes, new in Conquests, can erupt, and the Clear Damage job repairs the squares they and heavy factory waste spoil, per the Complete manual (p. 117). 2K's page sums it up as "Beware the volcanoes" (2K).

Frequently asked questions

What does irrigation need in Civ 3? In Civilization 3 a square can be irrigated only next to fresh water (a river, a lake or another irrigated square) until you discover Electricity, per the Complete manual (pp. 59, 114). Irrigation adds 1 food on Flood Plains, Grassland, Plains and Desert.

How do you build railroads in Civ 3? In Civilization 3 Workers can lay railroad on a square that already has a road once you know Steam Power and have both Iron and Coal, per the Complete manual (pp. 116-117). Moving along a railroad costs nothing, and it raises the yields of irrigation and mines.

How many shields does clearing a forest give in Civ 3? Clearing a Forest in Civilization 3 gives 10 shields to the nearest city, per Prima's Official Strategy Guide (p. 43); the Complete manual says only "a number of production shields". The forest usually becomes Plains.

How do you make Workers faster in Civ 3? In Civilization 3 you can stack Workers (two work twice as fast), play an Industrious civilization, and research Replaceable Parts, which doubles every Worker's rate, per the Complete manual (pp. 26, 112, 127).

What does pollution do in Civ 3? In Civilization 3 a polluted square produces nothing until a Worker cleans it, per the Complete manual (p. 89); Prima's 2001 guide says its output is halved. Mass Transit and Recycling Centers reduce it.

What causes global warming in Civ 3? Civilization 3 bases the chance of global warming on the world's total population and the pollution points of all cities, not on polluted squares, per Prima's guide (pp. 53-54). It turns coastal land wetter and inland land to Desert, and nuclear blasts make it more likely.

What happens when you capture a Settler in Civ 3? A captured Settler becomes two Workers in Civilization 3, and captured Workers keep their old nationality, per the Complete manual (pp. 56-57). New players can find more early Worker advice in the Beginner's Guide.

Sources

• Sid Meier's Civilization III Complete manual (Steam-hosted PDF), Atari and Firaxis Games, 2005
• Civilization III manual, First Edition (archive.org copy), Infogrames and Firaxis Games, Sep 2001
• Civilization III: Play the World manual (archive.org copy), Infogrames and Firaxis Games, 2002
• Sid Meier's Civilization III: Prima's Official Strategy Guide (David Ellis) (archive.org copy), Prima Games, 2001
• GD Column 17: Water Finds a Crack (Soren Johnson), Designer Notes, Jun 12, 2011
• Sid Meier's Civilization III, 2K, read Oct 22, 2026
• How To Play Your First Game Of Civ 3, Suede, Feb 12, 2020 (video)
• Civilization 3: Everything you need to know, Suede, Nov 12, 2025 (video)
• The 12 most powerful techs in Civ 3, Suede, Dec 28, 2024 (video)