For default game rule keep inventory All normal world will be true and nether , the end it cannot ..but I want keep all these for survival world And like skyblock when dead will drop the inventory.. How can I set can anyone tell me ?
Have you tried going to all of the worlds, and setting the gamerule to true in each of these? I noticed on servers, unlike single player, each world has its own level.dat file. So if one world has a level.dat file where it is still set to false you will not get to keep your stuff there!
In the worlds where you want players to keep their inventory when they die, you will have to do /gamerule keepInventory true. In the worlds where you want players to drop their inventory when they die, you will have to do /gamerule keepInventory false.
So you mean Should I go world , nether and the end Type three times Game rule keepinventory true? So whole survival world will be success for keep inventory?
Yes... You need to go to each world and type it. If you want players to keep their inventory, set it to true and if you don't, set it to false.