You may or may not have heard of them. World Building Guide Books are these types of guide books in where it explains every little detail about a universe/world. It can be from an already established 'verse, or one you make up entirely on your own! It can even include pictures and drawings, lists and charts and anything that is for that world! I'm in the process of making a guide book for world guide books. Or "a guide on how to make them". Have you ever heard of World Guide Books? Would you try making them if you could? Do you need more details to decide?