ToME WikiKhymChanur: If a particular dungeon is filled with a particular floor type, then that floor type should "dominate" other floor types. For instance, in 2.2.x, when you dig a granite wall in the submerged ruins, it will be replaced by normal floor, but should be replaced by deep water. In Mount Doom, cold/ice attacks can leave patches of ice, and water attacks (or fire attacks on ice patches) can leave shallow water. I don't think that these should be created in the first place, but even if they are, they should quickly disappear and be replaced by the surrounding lava.
DarkGod: In 300 a floor type can say what it would like to be replaced with. For example trees are replaced by grass and so on.
MayLith: Cool! 