[AgentME]

The modern Battle Royale mode evolved from multiplayer mods for Minecraft and then ARMA made shortly after the 2012 movie Hunger Games which provided the essential ideas all together (elimination, lots of players, must explore a huge map for items).

I think Minecraft can't be overrated as a vehicle for experimentation in multiplayer modes. Not only did the game have a huge modding and multiplayer community and have support for large player counts and maps, but it's unusually easy to create for and the game itself has no built-in structured competitive multiplayer gametypes, which means there's tons of demand for people to make gametypes from scratch and there's no built-in code for how matches work that needs to be worked around for new ideas to be attempted. Many other online games have specific ideas of how matches work built-in that reduce the demand for brand new gametypes and could make implementing a gametype where matches work differently daunting.