The DF world is composed of millions upon millions of isolated, self-contained worlds. You do not generate them, you merely try to find a world that is similar to the description that is input. They all exist within the void. These worlds vary greatly in size, but are all flat. The sky and sides of each world are surrounded by inpenetrable, but solid barriers. However, the bottom is made of ultra dense slade to create gravity. However, sometimes this slade has holes in it called "eerie pits", which lead into the void. Nothing can exist within the void, so it simply disappears. Another way to enter the void is to compress matter, a process most commonly referred to as "atom smashing" by the mortals. The DF world exists in a transient state between 2D and 3D, but the void is 3D. Compressing matter in such a way means it can no longer fit in the 2.5D world, and therefor, gets forced into the 3D void, in which it is obliterated. However, a number of methods were devised to store an infinite amount of 2.5D objects in a single "tile" of space, without introducing them to the void. By careful placement, objects can be lined up infinitely so that none of their particles actually take up the same point in space. The mortals call this "quantum stockpiling" because they are carefully lining up the individual subatomic particles of objects. A similar effect can be achieved with living creatures, but because they tend to move, it takes more time to line them up properly, and therefor they enter the "tile" more slowly as more living things try to occupy the same space.