Re: [Mac] Sims4 Game won't go into fullscreen

Since you are in "Windowed" mode, you should see the menu bar at the top of your screen (shows the Apple logo on the far left with Date and Time on the right). While you are running Sims 4, you should see an option called "View". Click on it and it should give you the option to go to Fullscreen.

To start the game, you can either log into Origin and start the game from there or you can create an icon for the Taskbar and launch the game from there. I launch my game from the Taskbar usually.