The problem is that proton DELETES physx files every time you launch it with steam (check the wineprefix and install all necessary things), What you need to do in order to play it is: installing as normal with steam, then let it run and say yes to the physx error, then install protontricks and run in your terminal: protontricks 1238020 physx Now DO NOT press play on steam Run mass effect 3 with wine selecting the prefix, type in your terminal WINEPREFIX=~/.steam/debian-installation/steamapps/compatdata/1238020/pfx wine MassEffect3.exe Now it should work :)