When I first started experimenting with world generators, I wondered why my terrain wasn't smooth (visible chunk boundaries). When I fixed the smoothness issue, I wondered why using the same seed would produce different features in the terrain. I would like to share some tips on using Randoms in world generation. In ChunkGenerators: Only use the provided Random object for features within chunk boundaries (dirt depth, adminium thickness). Use a common shared Random object for overall world terrain shape (OctaveGenerators) In BlockPopulators: Use the provided Random. It is seeded with a combination of the world's seed and the chunk's coordinates so you will get consistent results that are not affected by which chunks generate first. May your terrain be contiguous!