Overscan Compensation - Are the sides of the screen being cut off?
Different television/monitor manufacturers use different settings on their units. It's impossible to account for each and every one so occasionally some people will have issues with the image from their RetroPie system being clipped (cut off) around the edges. If you experience this issue the first thing you should do is check the manual for your television for an "overscan" setting. If your TV doesn't have that (or you can't find it), open the RetroPie menu and follow these steps.
ENABLE OVERSCAN COMPENSATION
It will be easier to use your keyboard for the following steps...
select ADVANCED OPTIONS
At this point it will ask you if you want to enable overscan compensation...
select YES to reboot the machine
Once the system reboots you should now notice that your image is no longer being clipped. Congrats! You're done.
As always, there is a lot more involved with the overscan settings on your Pi. If the steps in this guide do not solve your issue, please CLICK HERE to view the offical documentation for more information about Overscan and options.