There is a world level system that provides player specific difficulty (and loot!) scaling. The world level system only applies to Ranged Worlds.
To increase world difficulty a player must go mining with hostilities active (i.e. a player cannot have peaceful status). While mining players will find Demonic Ashes. These ashes can then be stored or used via right click to increase the player's current world level.
Note: Players cannot repeatedly mine in the same chunk. It's best to spread out and mine in a variety of areas.
Levels can be stored as Demonic Ashes again if a player obtains Barbarian Bones. Barbarian Bones can be sacrificed while a player has an increased world level to create new Demonic Ashes -- at a one-to-one ratio.
Upon death, a player's world level is cut in half (rounded down).
Currently the only way to obtain peaceful status is by wearing Peaceful Warrior Armor. While a player has peaceful status they cannot increase their world level, and if they have an increased world level it will decrease by one level every five seconds.
While a player has an increased world level a number of benefits can be seen:
While a player has an increased world level, the world also gets more hostile:
Note: Zombies spawned by The Apocalypse do take world level into account