How to Change the Resolution in "League of Legends"by Seth Amery ; Updated September 22, 2017
Like most modern computer games, "League of Legends" gives its players the ability to change the resolution. With this option, you can adjust your game's visuals if they appear stretched, and you can also improve performance by switching to lower settings. If your screen goes black when launching the game, you can also change this setting in your offline game files.
Open the game menu anytime while playing "League of Legends."
Select the video options to open a new dialog box. You'll be able to change your resolution along with several other video settings.
Click the drop-down menu beside "Resolution" and change it to your desired size.
Out of Game
Navigate to your "League of Legends" installation folder.
Double-click the "Config" folder and open "game.cfg" in Notepad.
Change the numbers beside "width" and "height" under "General." For example, if your game normally runs at 1600x900, it'll say "width=1600" and "height=900." Changing these values and saving the file causes your game to use these new settings the next time you launch it.
Your configuration file may not display resolution options. If it doesn't, you can just type them in yourself as above. Make sure it's under "General," however.