Other Requirements
A full version of Unreal Tournament 2004 patched to version 3270 or higher is required to play.
The linux patch 3270 can be downloaded here: http://download.beyondunreal.com/fileworks.php/official/ut2004/ut2004-lnxpatch3270-1.tar.bz2
Or if you intend to run a server, you could use the free dedicated server package from http://unrealtournament.com/ut2004/downloads.php#Server