Terrain Changer
New Artificial Plains Terrain Change: Change coast or lake terrain into plains; Change ocean terrain into plains.
As long as there is any feature or resource on the tile—such as forest, marsh, rainforest, geothermal fissure, floodplains, volcanoes, or strategic/luxury resources like horses, iron, pearls, marble, etc.—it cannot be modified.
Pottery: Unlocks plains terrain change. Tundra, desert, plains hills can be changed to plains.
Animal Husbandry: Unlocks grassland terrain change. Tundra, desert, grassland hills can be changed to grassland.
Sailing: Unlocks coast/lake terrain change. Tundra, desert, grassland, plains can be changed to coast or lake ; unlocks artificial plains terrain change. Coast or lake can be changed to plains.
Cartography: Unlocks artificial plains terrain change. Ocean can be changed to plains.
Masonry: Unlocks desert terrain change. Grassland, plains, desert hills can be changed to desert.
The Wheel: Unlocks tundra terrain change. Snow, tundra hills can be changed to tundra; unlocks snow terrain change, tundra, snow hills can be changed to snow.
Engineering: Unlocks tundra hills terrain change. Snow hills, tundra can be changed to tundra hills; unlocks snow hills terrain change, tundra hills, snow can be changed to snow hills.
Mathematics: Unlocks desert hills terrain change. Plains hills, grassland hills, desert can be changed to desert hills.
Apprenticeship: Unlocks grassland hills terrain change. Plains hills, desert hills, grassland can be changed to grassland hills; unlocks plains hills terrain change, grassland hills, desert hills, plains can be changed to plains hills.
Grassland ↔ Plains ↔ Desert (two-way conversion)
Grassland Hills ↔ Plains Hills ↔ Desert Hills (two-way conversion)
Snow ↔ Tundra (two-way conversion)
Snow Hills ↔ Tundra Hills (two-way conversion)
Land (Plains) ↔ Coast (two-way conversion)
Land (Grassland, Desert, Tundra) → Coast (one-way conversion)
Ocean → Land (Plains) (one-way conversion)
