Assuming your game is configured for full screen and not in some “backward compatible mode”.
I’d recommend for quickly adding iPhoneX support that you letterbox your game within the safe area.
Apple would rather you at least consider using the full screen such that your game displays content all the way to the edges. That will take more work and will likely require some structural changes to how you access winSize/VisibleSize/Origin/etc. It will likely require keeping the game view (or at least background) at normal full screen and adjusting UI and any touch targets such that they’re within the safe area.
Here’s some hacky code to support iPhone X (even when using Launch Storyboards or adding the new Launch image size). It’s essentially shrinking the EAGL view to “letter box” it within the safe area. Also has the small code required to defer home gesture to require a second swipe before going home or switching app.
Feel free to submit an update or otherwise comment with corrections.