In The Emperor’s Name
In The Emperor’s Name (also known as ITEN) is a set of rules for skirmish games set in the Warhammer 40,000 universe created by Games Workshop. ITEN allows you to create narrative games inspired by the adventures of characters such as Gregor Eisenhorn, Gideon Ravenor or Shira Calpurnia, or any of the millions of Inquistors, Arbitrators, Roque Traders, Explorators and other personalities of the Imperium — as well as their enemies, be they Xenos or Chaos.
http://iten-game.org/