Although the Duke Nukem 3D code has been released under the GPL, the game
data (graphics, sounds, levels, etc) is still proprietary, (c) 3D Realms.

To play the game, you must provide the data files. There are a couple of
options:

- Buy the game, and copy DUKE3D.GRP and DUKE.RTS file from the game CD to
  /usr/share/games/eduke32/ or your ~/.eduke32 directory.

  Note: DUKE3D.GRP should be named "duke3d.grp" (lowercase), but DUKE.RTS
  should be uppercase.

- Use the files from the shareware version, which is still available for
  download from the 3D Realms site. For convenience, you may install the
  eduke32_shareware_data package from slackbuilds.org, which simply creates
  a Slackware package from the files in the shareware Duke3D installer.

For information on playing user-created levels or other Build engine games
(such as Nam), see http://wiki.eduke32.com/ and http://www.eduke32.com/

If you want to play the HRP (High Resolution Pack), get the
eduke32_hires_pack package from slackbuilds.org