Everywhere you look, you will find battle royale. It feels like every game is trying to get in on that action, either chasing the trend or because the developers spend more time than they should playing battle royale modes in their spare time. Regardless of the reasoning, it is everywhere. Even in Civilization VI.
Free to all owners of Civilization VI, Red Death puts 12 players in a map that is constantly shrinking thanks to the Red Death. It closes in from all sides, cutting off hexes of destroyed cities and oceans of acid with a mighty radioactive storm.
12 players are pitted against one another in this last civilization standing mode, though there are maps for two-player duels too. Or you can play against the AI if you prefer.
Unable to build, you control several units: a bunch of combat units and a civilian unit. Should that civilian unit die or be captured you are out of the match. It is up to you to explore the map for extra units and get some XP. Then the Red Death will force you towards other players and AI-controlled enemies and outposts.