一款完美的rpg游戏，目的是为了清晰地描述用户使用本软件必须要完成的任务和定义开发人员必须实现的软件功能，使用户利用系统能够完成他们的任务。-A perfect rpg game, the purpose is to clearly describe the user-defined tasks and the software developers must be completed must implement software features, allowing users to use the system to complete their tasks.