Fortnite, Warzone, Hunger Games, and PubG only exist because of this movie...
Battle Royale is the Japanese film from 2000 that started the genre of open map survival fighting games and movies.
In the movie, 42 students are put on an island and only one is allowed to leave. They pick up gear and weapons on the map and use it to survive. The movie itself was adapted from a book by Koushun Takami released in 1999 which the author admits was inspired by the 1954 novel "Lord of the flies"
On the other hand, Suzanne Collins, the writer of the Hunger Games denies all links to her book and Battle Royale altogether. Which she was forced to do after Quentin Tarantino said the film based on her book was a blatant rip-off of Battle Royale, instead she states her book was inspired by the greek myth of "Theseus and the Minotaur"