This file is located in the Rappelz game client install folder and it is used to save your customized options from one launch of the game client to the next. Some players prefer to use the in-game Option Setting window to tweak options. Access that GUI using Alt+O in game. There are two tabs available in that window: 1. * Game Environment 2. * Game Play Others like to tweak the options in a text editor such as Notepad or WordPad. If you do edit the file in a text editor then don't expect your changes to take effect until the next launch of the game client.