The decision has been made based on test player feedback
Video game developer Blizzard says that once the 1.0.7 patch launches for Diablo 3, the dueling mode that many players have been using will be renamed to brawling in order to better reflect the actual mechanics of the experience.The team says in an official update that, “Sure, it allows players to pummel, stomp, immolate, and hex fellow Nephalem, but it’s not a traditional one-on-one duel. It’s something much more wild and open-ended, where you can engage in 3-person and even 4-person free-for-all skirmishes with few restrictions.”
Apparently, many players who have experienced dueling on the test servers for Diablo 3 have suggested the name change in order to make sure that all those who try the mode understand what they are signing up for.
Update 1.0.7 for Diablo 3 will introduce a number of other changes to the hack and slash title from Blizzard.