Terrain serves three roles: the theater upon which your units battle rival civilizations, the landscape across which your units travel, and the medium which your cities work to produce resources. The different types of terrain each have different strengths and drawbacks; see the sections on each terrain type for details.
Terrain affects combat very simply: when a unit is attacked, its defense strength is multiplied by the defense factor ("bonus") of the terrain beneath it. (However, some types of units do not enjoy this bonus;) See the help section on Combat for further details.
Terrain can complicate the movement of units. For instance, moving onto rough terrain such as Mountains can cost land units more than flat terrain like Plains, although sea and air units always expend one movement point to move one tile.
Tiles within range of a city may be worked by that city to produce food, production, and trade points, and the quantity of each produced depends on the terrain. These three products are so important that we specify the output of a tile simply by listing them with slashes in between: for example, "1/2/0" describes a tile that each turn when it is being worked produces one food point, two production points, and no trade points. In addition to the characteristic output of the terrain, some tiles have an additional special resource that boosts one or two of the products. See the Economy section for more information on the use of these products.
The net benefit of a tile for your city depends on your government type as well as city improvements and wonders.
It is possible for your units to change the terrain and hence its effects. see the section on Terrain Alterations for more details.
* You cannot build cities on this terrain.
* Paths cannot be built on this terrain.
* Bases cannot be built on this terrain.
* The coastline of this terrain is unsafe.
* Units on this terrain may impose a zone of control, or be restricted by one.
* Units able to fortify may do so on this terrain.
* No Pollution nor Fallout appear here.
No unit can enter this terrain, nor can any city work its tiles.
* Prevents to build Aqueduct.
* Allows to build Aqueduct, Lake (with Carpentry).
* Prevents to build Aqueduct, River.
* You cannot build cities on this terrain.
* Can be traveled by Missile, Sea, Coaster, Hovercraft, Helicopter, Air, Bomb, Riverboat, and Torpedeos units.
* Units on this terrain neither impose zones of control nor are restricted by them.
* No units can fortify on this terrain.
* No Pollution nor Fallout appear here.
Lakes are substantial bodies of fresh water.
* You cannot build cities on this terrain.
* Can be traveled by Missile, Sea, Coaster, Hovercraft, Helicopter, Air, Bomb, and Torpedeos units.
* Units on this terrain neither impose zones of control nor are restricted by them.
* No units can fortify on this terrain.
* Allows cities to build Harbors and coastal wonders.
Shallow oceans are mostly found near coastlines, and are often rich sources of food and other resources.
* You cannot build cities on this terrain.
* Paths cannot be built on this terrain.
* Can be traveled by Missile, Sea, Helicopter, Air, Bomb, and Torpedeos units.
* Units on this terrain neither impose zones of control nor are restricted by them.
* No units can fortify on this terrain.
* Allows cities to build Harbors and coastal wonders.
* No Pollution nor Fallout appear here.
Deep oceans cover much of the world away from coastlines, and only seaworthy units (not Coasters) can travel on them.
* You cannot build cities on this terrain.
* Can be traveled by Missile, Infantry, Small Land, Merchant, Helicopter, Air, and Bomb units.
* Units on this terrain may impose a zone of control, or be restricted by one.
* Units able to fortify may do so on this terrain.
* Mine can be upgraded to Oil Well.
Glaciers are found only in the most northerly or southerly reaches of the world. They are very cold, and hence difficult to work with.
Land units (except of small ones, including Alpine Troops) can't move on Glaciers without an appropriate roads.
* Allows to build Kaaba (with Islam and Mosque but no Temple, Church, Cathedral, Michelangelo's Chapel, J.S. Bach's Cathedral, King Richard's Crusade, Kyoto Fushimi Inari, Colossus, or Western Wall).
* Can be traveled by Missile, Infantry, Small Land, Light Cavalry, Heavy Cavalry, Big Land, Merchant, Hovercraft, Helicopter, Air, Bomb, Suicidal, and Wheeled Unit units.
* Units on this terrain may impose a zone of control, or be restricted by one.
* Units able to fortify may do so on this terrain.
* Mine can be upgraded to Oil Well.
Deserts are regions of extreme dryness, making agriculture and trade very difficult.
Rivers bring fertile soil to deserts; on a desert river not already benefiting from an oasis, building irrigation will yield two extra food resources rather than the usual one.
* Can be traveled by Missile, Infantry, Small Land, Light Cavalry, Heavy Cavalry, Big Land, Merchant, Helicopter, Air, and Bomb units.
* Units on this terrain may impose a zone of control, or be restricted by one.
* Units able to fortify may do so on this terrain.
Forests are densely wooded, making agriculture somewhat problematic.
Road or river required to get additional production. Paved road required for Wheeled units to move.
* Can be traveled by Missile, Infantry, Small Land, Light Cavalry, Heavy Cavalry, Big Land, Merchant, Helicopter, Air, and Bomb units.
* Units on this terrain may impose a zone of control, or be restricted by one.
* Units able to fortify may do so on this terrain.
Taiga are boreal forests with poor soil.
Road or river required to get additional production. Paved road required for Wheeled units to move.
* Can be traveled by Missile, Infantry, Small Land, Light Cavalry, Heavy Cavalry, Big Land, Merchant, Hovercraft, Helicopter, Air, Bomb, Suicidal, and Wheeled Unit units.
* Units on this terrain may impose a zone of control, or be restricted by one.
* Units able to fortify may do so on this terrain.
Grasslands afford exceptional agricultural opportunities.
* Can be traveled by Missile, Infantry, Small Land, Light Cavalry, Heavy Cavalry, Big Land, Merchant, Helicopter, Air, and Bomb units.
* Units on this terrain may impose a zone of control, or be restricted by one.
* Units able to fortify may do so on this terrain.
In addition to being amenable to agriculture, Hills are frequently rich in resources.
Cities built on hills are at risk of earthquakes, which can interrupt a city's current project.
Road or river required to get shield production. Paved road required for Wheeled units to move.
Saltpeter add extra 2 trade points to Infantry Barracks II.
* Allows to build Mahout Barracks (with Jainism).
* Can be traveled by Missile, Infantry, Small Land, Light Cavalry, Heavy Cavalry, Merchant, Helicopter, Air, and Bomb units.
* Units on this terrain may impose a zone of control, or be restricted by one.
* Units able to fortify may do so on this terrain.
Jungles are densely overgrown, making agriculture somewhat problematic, but substantially increase defense strength. Big Land and Wheeled Units may not move into jungle without a Paved Road.
Road or river required to get shield production, Railroad and Railway Station for additional shield production.
Elephants add extra 2 trade points to Mahout Barracks.
* You cannot build cities on this terrain.
* Can be traveled by Missile, Small Land, Coaster, Hovercraft, Helicopter, Air, Bomb, and Riverboat units.
* Units on this terrain may impose a zone of control, or be restricted by one.
* No units can fortify on this terrain.
* Allows cities to build Harbors and coastal wonders.
Mangrove are small trees that grows partially submerged by water, it is hard accessible area, only Small Land units, Hovercraft or some ships (Coasters, Riverboats) can pass trough Mangrove.
It is not possible to build advanced roads on Mangrove, only Dirt Road or Railway is available.
* Allows to build Cement Plant (with Concrete, Railway Station, and Factory but no Research Lab).
* You cannot build cities on this terrain.
* Can be traveled by Missile, Small Land, Helicopter, Air, and Bomb units.
* Units on this terrain may impose a zone of control, or be restricted by one.
* Units able to fortify may do so on this terrain.
Mountains are regions of extreme altitude, making agriculture and trade very difficult.
Reconnaissance (military Small Land) units that move into mountains can see an extra space, but a fast land unit ending its turn in mountains without a road will start its next turn with one fewer movement point. Land units (except small ones, including Alpine Troops) may not move into mountains without an appropriate road.
Road is required to get shield production.
Uranium is required for Manhattan Project and add extra 2 trade points to the Nuclear Plant.
* You cannot build cities on this terrain.
* Can be traveled by Missile, Small Land, Air, and Bomb units.
* Units on this terrain may impose a zone of control, or be restricted by one.
* No units can fortify on this terrain.
Active volcano is rather not suitable to live here.
* Can be traveled by Missile, Infantry, Small Land, Light Cavalry, Heavy Cavalry, Big Land, Merchant, Hovercraft, Helicopter, Air, Bomb, Suicidal, and Wheeled Unit units.
* Units on this terrain may impose a zone of control, or be restricted by one.
* Units able to fortify may do so on this terrain.
Plains are very broad, sparse regions, which makes agriculture farming slightly inconvenient.
Horses add extra 2 trade points to Stables Barracks.
* Can be traveled by Missile, Infantry, Small Land, Light Cavalry, Merchant, Hovercraft, Helicopter, Air, and Bomb units.
* Units on this terrain may impose a zone of control, or be restricted by one.
* Units able to fortify may do so on this terrain.
Swamps suffer from an over-abundance of water, making agriculture somewhat problematic, but can be irrigated even without adjacent water source and therefore allow to irrigate adjancent terrain. It is not possible to make Farmland on Swamp. Big Land and Wheeled units may not move in swamps without a paved road, Heavy Cavalry require at least dirt road.
* Can be traveled by Missile, Infantry, Small Land, Light Cavalry, Heavy Cavalry, Big Land, Merchant, Hovercraft, Helicopter, Air, Bomb, Suicidal, and Wheeled Unit units.
* Units on this terrain may impose a zone of control, or be restricted by one.
* Units able to fortify may do so on this terrain.
Tundra are broad, cold regions, fit for some agriculture and little else.
* Can be traveled by Missile, Infantry, Small Land, Light Cavalry, Merchant, Helicopter, Air, and Bomb units.
* Units on this terrain may impose a zone of control, or be restricted by one.
* Units able to fortify may do so on this terrain.
Wooded hills provide significant defense bonus, but can't be improved by mining - primeval forest need to be grubbed up first.
Road or river is required to get additional production. Paved Road required for Big Land or Wheeled Units to move.