The binaries will look for .wad files in:
* ~/config/non-packaged/data/prboom-plus
* ~/config/non-packaged/data/doomdata
* ~/config/non-packaged/data/doom
* ~/config/settings/prboom-plus
* ~/doom
* /boot/system/non-packaged/data/doomdata
* Any compatible game data package
The binaries can be also used via command-line with the -iwad command.
Example: 'prboom-plus -iwad /path/to/doom/doom.wad'