Urban Terror, commonly abbreviated as UrT or UT is a total conversion mod of id Software's first-person shooter Quake III Arena by Silicon Ice Development (hereafter referred to as FrozenSand). It introduces many elements of the tactical shooter genre — team-driven gaming in more realistic environments.
The game itself is free of charge, but FrozenSand retains the rights; unauthorised modification and selling is not allowed. Since Urban Terror 4.0, the game is normally played with the ioUrbanTerror engine, which is a rebranding of the ioquake3 engine distributed under GNU General Public License. Previously, the game was played as a mod that required Quake III Arena.
The mod was nominated to the 2007 Mod DB's Mod of the Year Award.