Wonderful idea. I strongly believe if this idea gets implemented, players will return and give MCNR a try again; that's including myself.
Dueling in jail has been a topic for so long and it's so nice and refreshing to see people are finally willing to give it a try. I personally know a lot of people who have told me that the lack of jail duels have resulted them in leaving the server, so no doubt this will attract them back.
