The Riot Games Champion Mastery API retrieves Champion Mastery data for the League of Legends game. Use it to Get all champion mastery entries sorted by number of champion points descending, Get a champion mastery by player ID and champion ID and Get a player's total champion mastery score. Champion Mastery is a progression system in League of Legends which tracks a player's aptitude and experience with each champion. This API requires an API Key and token for authentication and authorization. Riot Games provides the game developer community with access to game data programmatically and builds tools to develop, publish, and support player-focused games globally.