Ever wanted to duel your friend in Diablo 3? Fortunately, it’s on the list of new features to be added in the next patch to Diablo 3, version 1.0.7. The way it is set to work is that you can go to the Inn at New Tristram and talk to Nek the Brawler (appropriate enough), and from there, you’ll be teleported to an area that’s all set for dueling. For those of you who have hardcore characters, don’t worry, death inside the dueling arena isn’t permanent, even for you. So go ahead and ready up to beat your friends!
Source: Joystiq