Concept work for a fighting game called Assassin’s Creed Duel has been leaked today. The concept work was listed on a portfolio belonging to former artist and UI designer for Ubisoft. Though the designer has moved on to Eidos, his work has obviously stuck around. The images say that AC Duel was not a game and just a concept so there is no word saying that this was a working game or not. Either way it is an interesting look at something that could have been.