Heretic

What works: HERETIC.WAD from Heretic: Shadow of the Serpent Riders (1.3) or the original 1.0 release: a CD, an installed copy, Steam's folder or the GOG installer.

• With Walnut Games (the easy way)
• With game-data-packager (a terminal, any Debian system)
• By hand (the files, where they go, their checksums)

1. With Walnut Games

In Walnut Games, open Heretic: Install, then Add game files... The chooser lists the disc in the drive, mounted discs and USB sticks, GOG and Steam folders, and the ISOs, installers and archives in Downloads and your home folder; you can also pick a file or folder yourself. It checks every file against the checksums below and installs an ordinary package (heretic-wad), which Remove data takes away again.

In a terminal, the same with walnut-data (part of Walnut Games):

walnut-data import heretic /path/to/your/copy

A source is the disc in the drive (/dev/sr0), an ISO (.iso, .img), a BIN/CUE image (the .cue, or the .bin with its .cue next to it), an Alcohol 120% image (the .mds, or the .mdf), an installer or archive (GOG's setup_*.exe) or a folder (an installed copy, Steam's or GOG's). Images are opened read-only; nothing is copied out of them that the game doesn't need.

With Walnut's licensed suite as an apt source, the app offers Install from Walnut licensed instead (walnut-data install-repo heretic). walnut-data remove heretic takes the data away again.

2. With game-data-packager

walnut-data runs game-data-packager, Debian's tool that makes a package out of game data: Walnut's build of it (Debian's 89 with our patches) comes with Walnut Games. Run it yourself to keep the .deb, or to make it on another computer. It writes <package>_<version>_all.deb into the folder after -d (. is the current one), one package per -p:

Then install the file it made, from the same folder:

sudo apt install ./heretic-wad_*.deb

• --no-download: only your files are used.
• It reads a folder, an installer or an archive; it doesn't open disc images. Mount an ISO first (open it in the file manager, or udisksctl loop-setup -r -f FILE.iso, then udisksctl mount -b /dev/loopN) and give it the mount point, or let walnut-data do it. BIN/CUE and MDF images: walnut-data only.
• Walnut's patches that concern this game: Accept Doom II 1.666 and Heretic 1.0 as doom2-wad and heretic-wad. Debian's own game-data-packager doesn't have them, so it may refuse some of the copies above.

3. By hand

Copy the files to the paths below as root (sudo cp), with the names exactly as written, upper and lower case included: Linux tells them apart. Where a file has several accepted versions, any one of them does. Check a copy with sha256sum FILE (sha1sum or md5sum where the table says so) and compare the sum. Files copied by hand belong to no package: Walnut Games goes by the packages, so it still shows the data as missing, and Remove data leaves them alone.

heretic-wad (full)

Into /usr/share/games/doom, 10.6 MB.