Wolfenstein: Enemy Territory (abbreviated as RTCW:ET, WOLF:ET, W:ET, WET, and among many regular players simply ET) is a freeware first-person shooter (FPS) computer game, and a standalone sequel to Return to Castle Wolfenstein, created by Splash Damage.

Enemy Territory was originally planned to be released as a commercial expansion pack to the popular FPS Return to Castle Wolfenstein and later as a standalone game. However, due to problems with the single-player aspect, the multiplayer portion was released on May 29, 2003 as a freeware standalone game. In early 2004 the source code for the game logic (not the game engine) was released to the benefit of its modding community. The game uses a modified RTCW engine, itself being a modified Quake III: Team Arena engine (which has been open-source since 2006).

Make sure that the driver to your 3D graphic card is proper installed and working.

Download ET loki installer to your system, thereafter open the terminal;

cd ~/Desktop
wget -c http://ftp.games.skynet.be/pub/wolfenstein/et-linux-2.60.x86.run

Code:

cd ~/Desktop
sudo sh et-linux-2.60.x86.run

Enemy Territory should appear in your applications list (typically either Games or Other).

Enjoy!