Board Thread:Speculation House/@comment-24267097-20150326031823/@comment-25555436-20150326034104

-Wait, wood is renewable?

-I see Dust as Oil; it's pretty much common around the world, used for almost-everything, important to civilizations, and not to mention their use in combat. However, unlike oil, if Dust is not renewable at all, then if it runs out completely, the kingdoms will be doomed, both because they will lack their main energy source for almost-everything, and because Dust is a valuable weapon against Grimm (it was what saved mankind's ass).

Of course, people have been using Dust since supposedly ancient times, before the kingdoms, back when the Grimm were an actual threat. And there are still millions of Dust everywhere in the kingdoms and out of them. So either they exist in very goddamn high amounts, or mankind learned to how renew them.