Terrain.mp

Quick Jumps:

Terrain Chart

Terrain Modification Flowchart

World

The Freeciv world map is made of tiles (squares). Each is some type of terrain. The eastern and western edges connect, forming a cylinder that can be circumnavigated.

Terrain

Terrain affects 3 facets: (1) Unit combat, (2) Unit movement, (3) Resources for cities. We shall consider each facet in turn.

Unit Combat

Terrain affects combat. When a land unit is attacked, its defense strength is multiplied by the bonus of the terrain. See the page on combat for details, and the Terrain chart below for which terrains offer bonuses. (Rivers give an extra bonus of +50%.)

Unit Movement

Sea and air units always expend one movement point to move one tile. Terrain only influences the movement speed of land units.

Land units - movement "speed":

Moving across easy terrain costs one point per tile; moving onto rough terrain costs more. The cost for each difficult terrain is given in the Terrain chart below.
The explorer, partisans, and alpine troops travel light enough that moving one tile costs only ⅓ of a movement point. (They can use railroads like anyone else.)
Other land units spend ⅓ of a movement point per tile along rivers and roads, as long as the tile they are leaving also has a river or road.
With Railroad technology, roads can be upgraded to railroads. Units can move as far as they want along a railroad in a single turn! Beware that roads and railroads can help an enemy army as much as your own.

Cities always have roads inside — and bridges and railroads if the nation has those respective technologies.

With the Bridge building advance, roads and railroads can be built on river tiles to bridge them.

Resources for Cities

Tiles within range of a city may be worked by that city. Cities may be built on any terrain except Ocean or Glacier.

When a city works a tile, it receives three products: food, production, and trade. Output of a tile is conventionally written as food/production/trade. For example, "1/2/3" is a tile that produces 1 food, two production, and 3 trade.

Terrain sometimes has a special resource which boosts food, production, or trade. Terrain transformation can make resources inaccessible; for instance, if a Forest with a pheasant is transformed to Plains, it will lose its food bonus.

The terrain Terrain chart below lists the output of each terrain, both with and without special resources.

Improving Terrain

Mining and irrigating are the two actions that workers, settlers, and engineers can do to improve terrain. Transforming is a third action that only engineers can perform.

As soon as they are created, workers, settlers, and engineers can "irrigate" land to produce more food, cut a forest, or drain a swamp; or, "mine" a tile to yield more production points, plant a forest, or create a swamp.

Irrigation and mines can't co-exist on the same tile. Once built, a mine or irrigation system may will be destroyed if replaced with the other improvement.

To irrigate land, the player must have a water source in one of the four adjoining tiles. Water sources are oceans, lakes, rivers, or any other irrigated land except a city tile.

Terrain can be transformed into a new type. Attempting to irrigate a forest, for example, creates plains. (See "Terrain Modification Flowchart" below.)

Roads and railroads can be built on the same tile as other improvements (such as irrigation). Note that roads and rivers enhance trade for some types of terrain, and railroads increase the production output of a tile by 50%.

Later improvements

Fortresses (requiring Construction) and Airbases (requiring Radio) are also terrain improvements.

In a Fortress, enemies can only kill units one at a time instead of all at once, and defence is doubled. Fortresses also claim and extend national borders. Once Invention is discovered, units in a fortress have increased vision.

In an Airbase, air units (including helicopters) are also killed one by one and allowed to refuel, but are open to attacks by land units. Paratroopers can be launched from airbases.

After Refrigeration has been discovered, irrigated tiles can be irrigated again, resulting in farmland. This increases tile food production by 100% if the city working it has a supermarket.

Only engineers can directly transform land. (See terrain improvement chart above.) For transforming swamp to ocean, one of the eight adjoining tiles must be ocean already. To transform ocean into swamp at least 3 of 8 adjoining tiles must be land. To work on Ocean, Engineers must be on a transport. The new swamp will get a river if built adjacent to some river tile's single mouth.

Engineers work at double speed and perform two worker-turns per turn. Therefore they complete all improvements in half the number of turns specified in the terrain improvement chart and Terrain chart.

Two or more units working on the same tile under the same orders combine their labor, speeding completion of their project. Be careful: when a unit's working orders are interrupted, its progress is lost.

Any special resource on a tile is lost after its terrain type is transformed. It would reappear if the tile can be transformed back to its original terrain.

Rivers

Rivers increase movement the same as roads while giving a +50% defense bonus. Roads can't be placed over river tiles until the technology Bridge Building is discovered. A tile with a river gives trade the same as a tile with a road. On grassland, plains and desert, a tile with a bridge will give an extra +1 trade more than a road. On other terrain, bridges give no trade bonus.

Terrain Chart

Terrain	F/P/T	Special 1	F/P/T	Special 2	F/P/T	_{Move cost • Defence}	Result: _Irrigation(turns)Mining(turns)	Result: Road (turns)_{Transform (turns)}
Deep ocean	1/0/2					1M 1×	✘ ✘	✘ ✘
Desert	0/1/0	Oasis	3/1/0	Oil	0/4/0	1M 1×	+1F (3) +1P (3)	+1T (1) Plains (12)
Forest	1/2/0	Pheasant	3/2/0	Silk	1/2/3	2M 1.5×	Plains (3) Swamp (8)	+0T (2) Grassland (12)
Grassland	2/0/0	Shield	2/1/0			1M 1×	+1F (3) Forest (5)	+1T (1) Hills (12)
Hills	1/0/0	Coal	1/2/0	Wine	1/0/4	2M 2×	+1F (5) +3P (5)	+0T (2) Plains (12)
Jungle	1/0/0	Gems	1/0/4	Fruit	4/0/1	2M 1.5×	Grassland (8) Forest (8)	+0T (2) Plains (12)
Lake	1/0/2	Fish	3/0/2			1M 1×	✘ ✘	✘ Swamp (18)
Mountains	0/1/0	Gold	0/1/6	Iron	0/4/0	3M 3×	✘ +1P (5)	+0T (3) Hills (12)
Ocean	1/0/2	Fish	3/0/2	Whales	2/1/2	1M 1×	✘ ✘	✘ Swamp (18)
Plains	1/1/0	Buffalo	1/3/0	Wheat	3/1/0	1M 1×	+1F (3) Forest (8)	+1T (1) Grassland (12)
Swamp	1/0/0	Peat	1/4/0	Spice	3/0/4	2M 1.5×	Grassland (8) Forest (8)	+0T (2) Ocean (18)
Tundra	1/0/0	Game	3/1/0	Furs	2/0/3	1M 1×	+1F (3) ✘	+0T (1) Desert (24)