Change Terrain is an Uncommon Instant Spell belonging to the Nature Magic realm. It may only be cast on the overland map. For the base Casting Cost of 50, it will change a targeted tile from one terrain type to another. Most terrain tiles are shifted one "step" closer to Grassland, and Grassland may be changed back into Forest. Several types of terrain, including Oceans, may not be targeted. The effect is permanent and does not require an Upkeep Cost to maintain.
Change Terrain will alter the terrain in a single tile. The terraforming effect will flatten mountains and generally work towards turning the tile into Grassland.
Below is the table of terraformation, including all terrain types that may be affected by Change Terrain:
The terraformation generally makes the target tile easier to move through, but its primary purpose is to work to increase the Food output of any nearby Town at the expense of Production. The reverse is true when terraforming a Grassland tile, since it changes into a Forest (better Production, less Food).
Terraforming does not alter any Terrain Specials present on the targeted tile. Therefore, you can end up with Adamantium Ore on Grassland tiles, for example. Encounter zones such as Lairs or Towers of Wizardry are not affected either.
Change Terrain may only be cast on the overland map, for a basic Casting Cost of 50. It must be targeted at one of the valid terrain types, including Grassland, Forest, Desert, Swamp, Hill, Mountain or Volcano. Other tile types may not be targeted. You may not target any tile containing a Node, either (exception: if a chaos node has been converted into a hill by Gaia's Blessing, Change Terrain can be used to convert the hill into grasslands).
The terraformation occurs instantly, accompanied by the visual effect of green sparkles. The tile is now considered to have its new type, so nearby Town Production and Food output will change immediately, and units may travel across the tile as appropriate for its new type.
The new tile type is permanent, and is not maintained by magic. Only the change itself is a result of the Change Terrain spell. The spell runs its entire course instantly, and therefore may not be dispelled after it has been cast, and does not require any Upkeep Costs.
You may cast Change Terrain repeatedly on the same tile, as many times as you wish. This is necessary for transforming a Volcano to a Grassland tile, for example (requires 3 castings of the spell, going from Volcano to Mountain, then to Hill, then to Grassland with the final casting).
Change Terrain is an excellent way for increasing the potential size of a nearby Town, and especially its Food output. It is also sometimes used to make it easier to travel through one's own lands. Casting Change Terrain on land near an enemy's towns is possible, but there are rarely any good reasons to do so.
Note: If you remove all hills, mountains and volcanos in a town's catchment the town will be unable to construct a Miners' Guild. Make sure to leave at least one of these terrain types unless you also have access to the Chaos spell Raise Volcano (or have built the structure already and are not worried about it getting demolished).
Customized Wizards possessing 11 Spellbooks at creation time may choose this spell as one of their default spells before starting the game, in which case the spell will already be researched and available for casting immediately on the first turn.
Wizards who possess at least 8 Spellbooks, or Wizards with 11 Spellbooks who did not select Change Terrain as a guaranteed spell, will be able to Research this spell at some point during their campaign. Wizards with fewer than 8 Spellbooks have a random chance of being able to Research it. The chance for this spell to appear increases with the number of Nature Spellbooks the Wizard possesses or obtains during gameplay.
Change Terrain has a base Research Cost of 500.
With at least 1 Spellbook, the Change Terrain spell may be acquired as a reward for winning encounters in creature Lairs, Towers, et cetera, or when conquering the Fortress of a rival wizard who has already researched this spell.