Before using the mod make sure you have installed Unstable Generation mod.
This mod is being used with Unpredictable SMP - UnpredictableSMP.aternos.me
If you want to support me play in our Server.
This mod fixes placing and breaking blocks under the nether's bedrock. Without "Underworld Behaviour" - Unstable Generation mod doesn't block placing/breaking blocks under the nether's bedrock, despite the fact that you cannot break or place blocks in the underworld itself.

