This mod is required for the Dome of the Dead modpack.
The mod keeps track of all mob and player deaths and tallies that up to create a "world control weight" number. This number is then used to determine the kind of loot that can be found inside of chests and boxes in the Dome of the Dead modpack utilizing Gamestages that are granted by this mod once a world control weight has been reached. Without explaining the specific math behind calculating weight, essentially mob deaths increase the number at a flat rate based on the mob's max health, where as player deaths decrease the number in a way influenced by the amount of mob deaths so far. Essentially dying early game is less consequential than dying late game. Players are able to monitor their progress to the next Gamestage using the included "VMP Monitor" added by the mod as well.
Theoretically, this can work independently from the modpack but with the included in game messages, may be confusing in a different pack or standalone. Unfortunately progression cannot be modified by a config file nor commands, its locked into its current rates as it is intended for use with the Dome of the Dead modpack.
Here's the list of Gamestage IDs the mod will grant players, in order:
rank1
rank2
rank3
rank4
rank5
rank6
rank7
rank8
rank9
rank10
rank11
rank12