Thievery UT

Thievery UT is a free mod for Unreal Tournament first released by Black Cat Games in 2001. Thievery uses the stealth gameplay and medieval/steampunk theme of Thief: The Dark Project and Thief II: The Metal Age but instead focuses on multiplayer. Thievery also predates Tom Clancy's Splinter Cell: Pandora Tomorrow, which proudly declares itself "the first-ever multiplayer stealth game".