It gets thrown around a lot, but truly, I don’t think that word “copyright” means what the plaintiffs here think it means. Now I realize that some lawyers will happily cash their hourly and represent a client with no standing, but this is sad. PUBG didn’t invent the concept in or out of gaming of the Battle Royale, and most of their assets weren’t their creation. They made a ton of money from an alpha product, good for them, it doesn’t entitle them to prevent competition from more competent companies.
The bottom line is that you can’t copyright broad gameplay mechanics, that’s not how it works.
Disclaimer: I don’t care for PUBG, or Fortnite, and can’t wsit for this latest “make everything Battle Royale!” fad to die.