Civilization IV: Strategy Articles
A Comprehensive Guide to Terrain, Improvements, Resources, and City Placement
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Table of Content:
- Terrain Values
- The Basics about Terrain
- Base Terrain and Terrain Features
- Cumulative Tile Values
- Worker Improvements
- The Basics about Workers
- Basic Worker Actions
- Worker Turns for Improvements
- Terrain Specific Improvements
- Base FPC Values for Improvements
- Other things to note about Improvements
- Chopping Forests
- How Terrain Modifies Improvements (detailed charts)
- Resources and Improvements
- The Basics about Resources
- Resource Improvements
- Added Bonuses Through City Improvements
- Resources and Terrain Types
- City Placement
- The Basics about City Placement
- Resource Bonuses for Cities
- Other Important Factors when Placing a City
- How Civics and Traits effect FPC
- Links to related guides
The guide will give you a complete breakdown of the types of terrain and their food, production and commerce values (FPC). There is a lot more to it than what is available in the manual or Civilopedia, and this guide is an attempt to cover as much of it as I can. There are five factors involved when using terrain effectively: terrain values, terrain feature values, improvement values, bonus resource values, and civics and tech bonuses--all of which accumulate. I've also made a list of worker improvements and their value modifications for each type of terrain. I've included the bonus value of resources as well; though the information is already in the manual, the way they calculated the values are unusual. I've recalculated them to make them more compatible with the other values in this guide. Having a more in-depth understanding of these terrain values can really help your strategy when deciding where to build your cities, and so I've also added a section on city placement strategies.
This guide was compiled by Stuporstar. I hope that people will find this guide useful. I will continue adding/correcting info as it comes. Special thanks goes to: Heroes for his best income breakdowns and added civics; EridanMan for his excellent guide on forest chopping; and Brokguitar for the most contributions so far, with his screenshots and much added info about terrain, resources and city placement.
PDF and text versions of this guide are available for download in the last section here.
Starting with the Basics: Yields (FPC)
There are three basic types of bonuses that terrain can give to your city: Food, Production, and Commerce. There are also two secondary bonuses, happiness and health, that are given by specific resources (and are a factor in trade) and some types of terrain features. For the moment we will focus on base FPC value. In the game, food is represented by bread slices, production is represented by hammers and commerce is represented by coins. For the purposes of this guide, food, production and commerce will be referred to as FPC.
In the game, FPC value is referred to as Yields. You can see the FPC value for terrain automatically when you click on a Settler unit. On your main screen you can toggle the Yields Display, which will reveal the FPC for every visible tile by either pressing Ctrl-Y,
or by clicking the Yields Display button on the bottom right-hand of your screen ==>
The Difference Between Commerce and Gold: I thought I'd mention this here because the two are easily confused. Both are represented by the coin symbol (which can be fairly easily modded into two separate symbols - I've created a mod for Gold myself which can be found here). Commerce comes from terrain, trade routes and your Palace, which is then divided amongst your sliders into Science, Culture (enabled with Drama tech) and Gold. The Gold then goes into your treasury or is used for city maintenance and civic upkeep. Because this guide deals primarily with terrain, we will mostly be referring to Commerce and not Gold values.
The Basics about Terrain:
The first thing we will discuss in this guide are the basic terrain, and terrain feature FPC values. Terrain features are things like forest, hills and floodplains which have cumulative values when added to the base terrain types underneath. Below is a screenshot showing the types of terrain and how these FPC values will appear over the tiles. Click the thumbnails for the larger version (saves on bandwidth):
As you can see, the best food producers are floodplain and oasis tiles, with 3 food; the best production tiles are plains/hill, with 2 production (3 with forest); and the best commerce comes from oasis and coastal tiles (including inland sea), with 2 commerce. Others, such as desert, and snow (and ocean) have no FPC value whatsoever, but can be modified by terrain features.
Base Terrain and Terrain Features
Below is a detailed list with all the FPC values listed for terrain types, as well as any health bonuses or penalties for cities, and movement costs and defense bonuses for units (base movement cost is 1mp).
F = food : P = production : C = commerce : mp = movement cost for units
Peak 0 impassible
Sea 1F 1C (Ocean = 0)
Coast 1F 2C (Inland Sea = 2F 2C fresh water source)
Plains 1F 1P
Ice 0 impassible
Jungle -1F (-0.25 health) always on grassland; 2mp; +50% defense bonus
Hills -1F +1P +25% defense bonus; 2mp
Forest 1P (+0.4 health) do not grow on desert/snow; 2mp; +50% defense bonus
Floodplains 3F (-0.4 heath) always on desert
Oasis 3F 2C (+2 health) fresh water source; always on desert; 2mp; cannot build cities
Rivers 1C (+2 health) fresh water source; +25% defense bonus
Rivers give no commerce bonus to Snow, Jungle or Forest tiles.
Note that when it comes to fresh water sources, they must be adjacent to your city for that city to get the health bonus, and you only get a total +2 health bonus to your city. It is not cumulative as it is with forest tiles.
Though forests will not grow on a snow tile, I have seen them randomly generated on the map so they will be covered in the next section.
Cumulative Tile Values
Listed below are the cumulative FPC value calculations when terrain features are added to base terrain types.
Grassland + Jungle 1F (2F - 1F)
Snow + Forest 1P (0 + 1P)
Tundra + Forest 1F 1P (1F + 1P)
Grassland + Forest 2F 1P (2F + 1P)
Plains + Forest 1F 2P (1F 1P + 1P)
Desert + Hill 1P (0 + 1P (-1F))
Snow + Hill 1P (0 + 1P (-1F))
Tundra + Hill 1P (1F + 1P - 1F)
Grassland + Hill 1F 1P (2F +1P - 1F)
Plains + Hill 2P (1F 1P + 1P - 1F)
Grassland + Hill + Jungle 1P (2F (- 1F + 1P) - 1F)
Snow + Hill + Forest 2P (0 ((- 1F )+ 1P) + 1P)
Tundra + Hill + Forest 2P (1F (- 1F + 1P) + 1P)
Grassland + Hill + Forest 1F 2P (2F (- 1F + 1P) + 1P)
Plains + Hill + Forest 3P (1F 1P (- 1F + 1P) + 1P)
These are the terrain/feature combinations that you will find on a randomly generated map. It is possible to add any terrain feature (and any improvement) to any kind of terrain in the World Builder, and they have corresponding cumulative values. These will not be covered however (for example putting a floodplain on a grassland tile will net you 5 food without improvements, which is so overpowered it might as well be cheating).
The Basics about Workers:
When you click to move a worker and mouse-over the terrain, you get a list of the types of improvements the worker can build on that square. In this example, the only option currently available on the highlighted square is a farm. The blue glow around the icon represents the AI's recommendation. The improvements that are grayed out are those that are available to that terrain (or resource) type, but have not yet been researched. When you mouse-over a tile it will also give you terrain info near the bottom left-hand corner, and in the case of a resource, will tell you which technology you need to research if you don't have it. A worker has two moves on flat terrain instead of one, but movement costs for forest, hills and jungles still apply. Moving onto the nearest flatland square means the worker can start working that tile right away.
Basic Worker Actions
Chop Forest: Chopping a forest becomes available with Bronzeworking, and chopping Jungle becomes available with Ironworking. It will not only clear land for other improvements (except Lumbermills) but will also give a production bonus to your nearest city. More about forest chopping and how it applies to strategy will be discussed later in this article.
Build Road: Workers can build roads on any tile (except impassible terrain) once the Wheel is researched. Unlike previous Civ games, roads do not give any FPC bonuses to tiles. They decrease unit movement costs by 1/2 (except in enemy territory), and decrease further to 1/3 with the Engineering tech. This effect of roads is negated across rivers until you get the Construction tech (little bridges appear). Roads are also used to establish trade routes between cities (rivers also work like roads in this aspect).
Build Railroad: Like roads, railroads can be built on any workable tile once Railroads is researched. They decrease movement cost by 1/10, and give a +1P bonus to mines and lumbermills.
Build Fort: Forts can be built on any workable tile once Mathematics is researched. They give units a +25% defense bonus. The disadvantage of forts is that they cannot be built on top of existing improvements. They destroy previously existing improvements and remove forests (kind of pointless when forests give a +50% defense bonus.
Scrub Fallout: This action becomes available with Ecology. Workers can remove fallout from nuclear strikes and nuclear plant meltdowns. Fallout make tiles unworkable and removes their FPC value. It also destroys forest and jungle tiles.
Worker Turns for Improvements
|Improvement||Base # turns||Forest (Chop+3 turns)||Jungle (Chop+4 turns)|
|Road||2||2 (no chop)||2 (no chop)|
|Railroad||3||3 (no chop)||3 (no chop)|
|Lumbermill||8||8 (no chop)||-|
|Camp||4||4 (no chop)||4 (no chop)|
|(+25%)||(+25% +3 turns chop)||(+50%)||(+25%)|
|Road||3||3 (no chop)||3||3|
|Railroad||4||4 (no chop)||5||4|
|Lumbermill||-||10 (no chop)||-||-|
|Camp||5||5 (no chop)||6||-|
Factors that increase worker speed are:
Techs: Steam Power - workers build 50% faster
Civics: Serfdom - workers build 50% faster
Buildings: The Hagia Sophia (World Wonder) - workers build 50% faster.
+8 culture, +2 Great Engineer. Tech required Engineering; Obsolete with Steam Power.
The tech and civic bonuses are cumulative, so it is possible to have your workers build 100% faster.
This chart was modified from Brokguitar's guide.
Terrain Specific Improvements
The list below lists the basic types of improvements you can build that are specific to terrain (resource specific improvements will be covered later in the resources section).
Desert = No improvements except Roads/Railroads
Flatlands: Grassland, Plains, Floodplains, Tundra (only with River) = Farm (only near river until Civil Service tech), Cottage, Workshop
Hills: (all terrain) = Mine, Windmill, Cottage (only on Grassland Hills)
Forest: (all terrain) = Lumbermill, Chop Forest (whatever you can build on the base terrain)
River: (all flatlands) = Watermill
Snow and Tundra = No improvements except Road/Railroad without River, Hills or Forest
Here is another screenshot by Brokguitar showing how the basic terrain-based improvements appear on the map and a comparison with the base terrain FPC values. Lumbermills on forested hill tiles and Workshops on floodplains are not depicted.
Base FPC Values for Improvements
Farm (flatlands, can only be built near rivers until irrigation; can build on resources)
Tech Required: Agriculture
Tech Modifier 1: Civil Service (spreads irrigation)
Tech Modifier 2: Biology (can build without irrigation) + 1F, only base 1F without irrigation
FPC Value: 1F
Best income: 2F (Biology with irrigation)
Mine (hills; can build on resources)
Tech Required: Mining
Tech Modifier 1: Railroads +1P with railroad
FPC Value: 2P
Best income: 3P (with railroad)
Cottage (flatlands, and grassland/hill)
Hamlet (10 turns)
Village (20 turns)
Town (40 turns)
Tech Required: Pottery
Tech Modifier 1: Printing Press Village +1C, Town +1C
Civic: Universal Suffrage (Democracy) +1P for Town
Civic: Emancipation (Democracy) +100% growth for Cottage, Village, or Hamlet
Civic: Free Speech (Liberalism) +2C for Town
Best income: 1P 7C (Printing Press, Universal Suffrage, Free Speech)
Tech Required: Metal Casting
Tech Modifier 1: Guilds +1P
Tech Modifier 2: Chemistry +1P
Civic: State Property (Communism) +1F
FPC Value: -1F 1P
Best income: 3P (Guilds, Chemistry, State Property)
Tech Required: Machinery
Tech Modifier 1: Replaceable Parts +1P
Tech Modifier 2: Electricity +1C
FPC Value: 1F 1C
Best income: 1F 1P 2C (Replaceable Parts, Electricity)
Watermill (only near rivers)
Tech Required: Machinery
Tech Modifier 1: Replaceable Parts +1P
Tech Modifier 2: Electricity +2C
Civic: State Property (Communism) +1F
FPC Value: 1P + 1C from river
Best income: 1F 2P 2C (Replaceable Parts, Electricity, State Property)
Tech Required: Replaceable Parts
Tech Modifier 1: Railroad +1P with railroad
FPC Value: 1P +1C to rivers
Best income: 3P 1C (1C from river, 1P from railroad, 1P from forest)
Note: the +1C to river tiles from Lumbermills is only returning the river bonus that you do not get on forest tiles.
Other things to note about some improvements:
Farms: As you can see from the previous chart, even with Biology, it is better to just chain your irrigated farms if you can, because the non-irrigated farms that this gives you the ability to build do not get the +1F irrigation bonus; however it may be useful if you are on a particular landmass that has no way of reaching fresh water and you desperately need to increase your food production. Once Civil Service is discovered, you can chain your farms if they are connected to a river or irrigated farm. You can in fact chain irrigation through cities; a city built on fresh water spreads irrigation to all adjacent tiles, provided it is built on flatland and not a hill. The only exception is on Tundra, which cannot have a farm built on it without being directly adjacent to a river.
Watermills: There are two exceptions where you cannot build a watermill on a river adjacent tile. When there is a bend in the river, you cannot build a watermill on the tile near the point on the bend (highlighted by the blue circle). You can still build watermills on the three other river adjacent tiles, however you also cannot build two watermills on opposite sides of the river. This means, that in this example, the tile directly below the workers cannot be turned into a watermill either because there is already one on the other side of the river.
Cottages: Cottages grow to produce more commerce. It takes 10 turns for a cottage to grow into a hamlet, 20 to grow into a village and 40 to grow into a town. It is a good idea to build these early to take advantage of their growth. However, this improvement will only grow if the tile is being worked by a citizen in your city. Normally you can see a little hut icon on the tile that is being worked, but with improvements those icons disappear, so if your cottages aren't growing, you may need to check which tiles are being worked in your city screen.
Chopping forests is a very useful strategy, especially early in the game. The production bonus you get from chopping a forest can help get your civilization to an early head start. However, keeping the forest will give you better production in the long run than if you chop it down to replace it with farms or cottages. The health bonus from forests is also useful. But it will take a while before you can research Replaceable Parts and build lumbermills. Here are some things to consider before you start deforesting your empire. Plan ahead, and think strategically.
Health Bonus: Keeping a few forests around have long term benefits to your cities health. You get a 0.4% health bonus to cities for every forest tile inside it's radius. You will also get +1 happiness in your cities with the Environmentalism civic (also for jungles).
Hills: On a forest/hill tile you only stand to gain 1P from replacing it with a mine, which you would eventually get back when you can build lumbermills. However that extra early production and the city production bonus you get from the chop is something to consider in exchange for waiting too long for equal production and added health benefit. I'll often leave hills forested until I've built more critical improvements first (unless I really need the bonus hammers fast and there's nowhere better to get them), but hills are a high priority for chopping once I find the time to build mines.
Rivers: Forests also take away the commerce bonus from rivers, which you will also eventually get back with lumbermills. Because you need as much commerce as possible, and the earlier the better, forests near rivers are usually on my high priority chopping list. There are too many better ways to use river tiles such as farms (early in the game) and watermills (much later).
Try to chop outside of your city borders (you can even chop outside your cultural borders!). The bonus hammers will go to the nearest city. There are distance modifiers, which means a forest chopped too far outside your borders will result in less hammers, but sometimes it's more worthwhile to keep those few forests within your city borders for the health effects.
The number of hammers you get from chopping will vary. The most consistent factor is game speed. A Quick game will average you about 20 hammers per chop, at Standard speed you will average about 30, and at Epic you will average about 45. Another factor is distance from your city; you will get less hammers the further away you chop. But what has the greatest effect on the number of hammers is production bonuses in your cities. Forges, factories, etc. and production increasing civics will all increase the amount of hammers you get by the percentage bonus you get for that city's production. The Industrious trait will also increase the number of hammers you get from chopping while building a wonder, because your wonder production is +50%. Having the right build materials for wonders (such as quarried marble to build the Oracle) will also double the amount of hammers you get from a chop while building it. Having the right building material for a wonder, plus any other production bonuses due to certain buildings and civics, will accumulate the number of hammers you get. I've heard it's possible to get 90 hammers from a single chop!
Chop before you improve. You get no turn penalties for chopping then improving, and you will get your bonus hammers that much earlier (3 turns). If you build an improvement on a forest tile, it will take you the time to improve the tile PLUS the time for the forest chop before you get your bonus hammers.
Forests (and jungles) will grow only on UNIMPROVED tiles as long as there is a forested square nearby. They do however grow over roads. I've tested and verified this by bumping up the forest growth percentage to something ridiculous and watching the forests grow all over the map. The chance of regrowth being calculated by the number of adjacent forest/jungle tiles is still up for debate, but it seems pretty random. There is currently no way to plant forests later in the game as there was in Civ III.
Defensive positions: The last thing to consider is the defense bonus and whether or not it is of strategic value to chop a forest or jungle. The defense bonus for both is 50%, and if that's on a hill (25%) you get a cumulative 75%! Because unit movement is also decreased, having a few forests in strategic positions around your empire can slow an enemy advance to a crawl. If you have a forest on a hill, in a good position for a fortification, DO NOT CHOP IT DOWN TO BUILT A FORT. A fort only has a 25% defensive bonus.
Much of this info I learned thanks to EridanMan's excellent guide in the CivFanatics forums.
A detailed breakdown of how worker improvements modify terrain values:
Summary: a breakdown of which terrain improvements maximize income/production/food best would be:
Food: Farm +2F (5F 1C best terrain) (+2F 1C with resource)
Commerce: Cottage +1P 7C (+1P 8C with river)
Production: Workshop +3P (1F 4P 1C best terrain)
Mine +3P (5P 1C best terrain) (+2P 1C with resource)
Lumbermill +3P (5P 1C best terrain) + health bonus from forest
General: Windmill +1F 1P 2C (2F 2P 3C best terrain) (1F 3P 3C best terrain)
Watermill +1F 2P 2C (2F 3P 3C best terrain) (4F 2P 3C best terrain)