X and Z coordinate restrictions

This is for Treasure Wars in particular.

Idea:
Set a boundary for how far out the player is allowed to build from the main map.
More info:
There’s already a boundary for how high a player can build, but since building outwards can cause players to fall, could it be a wither effect (constantly being set to 1 second) for when the player is building outside the range (with also a warning message)?

Ok i agree its like survival games on cubecraft