When you create a map with the Seed set at '100', you can generate an identical map by opening a new map with Seed 100. 'Seed' allows you to open a previous random map. You change the Type according to what area from the game you want to emulate in your map design. 'Type' defines which of the tile packages the editor will load for your map, the terrain type. The New Scenario window will open and present you with several options. Click File, then New to create a new map.
