0 A. D. (pronounced “zero ey-dee”) is a free open-source cross-platform real-time strategy game or ancient warfare. It is similar to Age of Empires.
THe game is historically-based war game that allows players to relive and rewrite the history of the Western civilizations, focusing on the years between 500 BC and 500 A.D.
This is how you install 0. A.D. on Ubuntu 13.04 Raring Ringtail, Ubuntu 12.10 Quantal Quetzal and Ubuntu 12.04 Precise Pangolin.
Add the repo:
$ sudo add-apt-repository ppa:wfg/0ad
Update the repo index:
$ sudo apt-get update
Install the game:
$ sudo apt-get install 0ad