This plugin is nothing more than Chess recreated in Minecraft, you can play with friends, compete with other players, create multiples arenas and test your logic. The first player to put the opponent's king in check is the winner of the game. You can even play vs the computer (paid version)!
If you don't know how to play, check the wiki: https://en.wikipedia.org/wiki/Chess
The plugin has most of the Chess rules, including movements and possible game ends.
Spigot / Paper 1.16.5+