I was just banned
So, you were just banned from your realm?
First of all, calm down, things happen. The middle ages were not a nice place, and to some extent, being arbitrary and unfair is as much part of the game as victory and defeat in battle.
If you were banned, you have one and a half day to find yourself a new home. If you were banned nicely (aka "asked to leave"), you get three days and can still use the realm's banks, workshops, etc. If you were banned as a traitor, you can't.
But I don't want to be banned!
Well, life is tough. You can, of course, try to talk the judge out of his decision. Some friendly words and a good explanation can go a long way.
Then again, maybe you did something bad or he's just unfair. So what? BattleMaster is a huge place, there's a lot of opportunities out there. Leave and go someplace else where you are more appreciated.
If you can make it to a port within the time available (1 and a half days), you can even leave the entire island.
But it's on my history now!
That's true, bans are recorded in your family history. Again, so what? Only a bad judge or ruler of some other realm will judge you because of one incident. If you have a number of like entries in your history already - well, then maybe they are justified?
On the other hand... "As for negative mark - you got a ban, be happy! It marks you as one of those people who dared to meddle with the people in charge. People with bans, in my experience, are more interesting than those without." (Alex Davies, on the mailing list)
That &$%/!* judge!!!
Hehe, excellent! Take your anger in-game. Try to be angry with your character, not as a player. Make a vendetta. Join an enemy realm and get them to support your feud (or join their war effort with zeal if they are already at war with your realm). Start a personal vendetta against that unjust judge. Try to stir up a rebellion while you're still in the realm. Challenge him to a duel (duels were quite commonly used as a means to find guilt or innocence in the middle ages!). There are a lot of ways to use a ban as a roleplaying tool to propel your character forward. It's not a setback, unless you make it one!