The world in Polytopia is randomly generated for each new game and consists of various types of terrain. Different terrain will provide different population or income boost to your cities, depending on how you use them. Terrain can also spawn with certain types of resources on them. Certain types of terrain will also stop you from moving through them (Forests and Mountains), but in the case of forests this malus can be circumvented with Roads.
Different tribes have different spawning rates for terrain and resources. When the map is generated at the beginning of the game, the land is distributed roughly equally between all tribes in the game (except Polaris). Generated resources have different rates which depend on the tribe. Terrain generation and starting technology are the only differences between Regular Tribes.
General probabilities for a tile to represent a certain terrain / have a certain resource are:
Mountain - 15%
Forest - 40%
Fruit - 50% (among Field tiles)
Crop - 50% (among Field tiles)
Game - 50% (among Forest tiles)
Fish - 50% (among Water tiles)
Whale - 40% (among Ocean tiles)
Metal - 50% (among Mountain tiles)
This table shows the tendency of terrain/resources to generate for each tribe's biome.
In addition, Kickoo and Aquarion have 40% and 30%, respectively, of their tiles replaced with water.
Resources such as fruit, wild animal, crop, fish and whale only spawn within 2 tiles of villages or cities, so you can use this to help you find more villages.
The design of field, fruits, forest, wild animals and mountain tiles will vary according to the tribe.
Any tile that is unexplored will be covered with a cloud. These will disappear when they come into the line of sight of your unit. Clouds also block your units from moving further until the cloud tile is explored. Clouds that disappear are only visible to the player who explores them so you can't see what AI or other players explored.
The default tile. Most normal buildings require this tile.
This tile does not block movement.
Ruins can spawn on this tile, although resources beneath it will not be revealed until the Ruin is cleared.
You can use Grow Forest on a field tile once Spiritualism is researched to convert it into a Forest tile, although this will remove all resources.
You may harvest fruit present on the tile for 2 stars yielding 1 population once Organization has been researched. This will turn it into an empty field.
Fish in ocean and Whales/Ruins in shallow water have been seen before, but are rare. Whales and Ruins appearing in shallow water occurs because of forced spawning. Bardur, Imperius, Kickoo, Zebasi, and Elyrion capitals have guaranteed resources in their capital, with resources being force-spawned if the initial world generation does not provide enough resources. In some cases, water tiles are replaced by missing resources, turning tiles with Whales/Ruins next to the newly force-spaned resources from ocean tiles to shallow water tiles. This is considered to be a bug.
Sometimes, this bug affects Mountain tiles, which will still provide the increased sight radius despite being replaced by a resource.