Fighting off-hand is not something anyone wants to do but if you lose your sword arm, it is required. I finally got to experience this at practice this past week. And I found out I am not too bad at it.

It is difficult to do because you are using the hand and arm that you normally don't do use for anything. You can't get in as hard of shots but they can and do connect and count. Most people will take a shot as a hit with off-hand without as much power because they know you can't hit as hard. Some won't. If you practice it long enough you might get to about the same strenght as your normal arm.

You have to fight with either a shield or second sword behing your normal arm when you go off-hand. It helps keep your arm down. Unfortunately some shots don't come off as you intend because it is your off-hand.