Notices by Eric Zhang 2: Episode 1 (eric@pl.starnix.network), page 12

@teto install northstar using the installer thing, open a terminal, run export STEAM_COMPAT_DATA_PATH=~/.steam/steam/steamapps/compatdata/1237970 && export STEAM_COMPAT_CLIENT_INSTALL_PATH=~/.steam/steam && export STEAM_APPS_PATH=~/.steam/steam/steamapps, launch the game in steam. when EA App™ is showing the preparing to launch window, you want to run northstar in the terminal window through proton as soon as possible. i am using proton 9 so the command i run is ~/.local/share/Steam/steamapps/common/Proton\ 9.0\ \(Beta\)/proton run ~/.local/share/Steam/steamapps/common/Titanfall2/NorthstarLauncher.exe. titanfall 2 w/ northstar should launch, minimize that window where it says only one instance of the game can be run at one time instead of closing it.