: If you have the original CD/DVD version, you can copy the files directly from the disc to your hard drive.
Sometimes a Steam or GOG installation skips a file, resulting in "Missing Map" errors or the infamous "Gray Box" textures.
Understanding and Acquiring Doom 3 PK4 Files In the world of .PK4 files
, you typically need to copy the following files from your legal installation's directory: pak000.pk4 pak001.pk4 pak002.pk4 pak003.pk4 pak004.pk4 pak005.pk4 pak006.pk4 pak007.pk4 pak008.pk4 If you are using the Resurrection of Evil expansion, you will also need the files located in the Linux Mint Managing and Extracting PK4 Files