On player death, there is a chance they are teleported to the death dimension. You choose what they have to do to get out. Navigate a maze, fight monsters, find a special item, and anything else you can think of!

/dd - The base command
/dd set - Sets the Death Dimension spawn point and world
/dd teleport - Teleports yourself to the death dimension!
/dd addworld - Enables the world you are currently in
/dd delworld - Disables the world you are currently in

deathdimension.admin - Allows access to all commands
deathdimension.immune - Makes you immune to teleportation to the death dimension

When a player dies, there is a customizable chance they are sent to the death dimension. The death dimension is set by you. You can create a separate world, or just a contained area, or whatever you want. You then set the spot with /dd set. Then when they are sent to the death dimension they are sent to that spot.

Once you have the plugin installed, go to the Death Dimension folder and open config.yml
Go to the worlds you would like to enable and do /dd addworld to enable them. When players die in an enabled world, there is a chance they are teleported to the death dimension!
Reload the plugin and enjoy! (Because OPs have death dimension.immune they will not be teleported to the death dimension.)