Rusted Kingdom has 5 worlds to play in.
QuestWorld: Most of the NPCs live here and quests happen mostly in this world. The difficulty is Easy. You can claim land here outside the quest area. The biome here is just flat grass outside of the questzone.
The Nether: This is a regular nether world. Some questing areas are found here. The difficulty is easy. You can claim land here for your kingdom.
The End: This world is a special questing area. No kingdoms land can be claimed here.
Kingdom: This world is where we recommend most players setup their bases. The difficulty is easy. No questing areas are found here.
Skylands: This world is a warped world where gravity is your enemy. The monsters here are also often insanely difficult, this world is only recommended for expert players. There are vast riches here to be found. Some quests are found here. If you are mad enough, you can claim land here for your kingdom.
