It's an adaptation of trivia. Each champion has like 200-word background lore, and the show is essentially an adaption of Jinx's and Vi's lore.

The main lore of LOL revolves around two factions resettling their differences by playing a game in which they possess powerful individuals (like Jinx and Vi).

So, a proper adaptation of LoL would be Hunger Games mixed with Jumanji: Welcome to the Jungle (in which the Rock plays the game character, Dr. Bravestone who is possessed by a nerdy high schooler).