Look for a line like: /home/you/.local/share/Steam/steamapps/compdata/#############/pfx/drive_c/…
Those ###s are Battle.net’s steam ID on your system.
Back on Steam, right-click Battle.net and click Properties.
Change the Target line to:
“/home/you/.steam/steam/steamapps/compdata/~your numbers~/pfx/drive_c/Program Files (x86)/Battle.net/Battle.net Launcher.exe”
Use Steam.
Download Battle.net Launcher.
Add it as non steam game.
Run it and install like normal.
Do not sign in. Close it.
In a terminal, type this: find ~ -name Battle.net
Look for a line like: /home/you/.local/share/Steam/steamapps/compdata/#############/pfx/drive_c/…
Those ###s are Battle.net’s steam ID on your system.
Back on Steam, right-click Battle.net and click Properties.
Change the Target line to: “/home/you/.steam/steam/steamapps/compdata/~your numbers~/pfx/drive_c/Program Files (x86)/Battle.net/Battle.net Launcher.exe”
Set Compatibility to Proton 10 beta.
Now launch Battle.net and install WoW.