Duels for sport (and guilds that encourage them) are illegal; however since the new training match option was added the concept of a dueling guild can find an appropriate game mechanics for their matches.
I didn't mean a guild which duels for sport but one in which people train a lot, brag about how well their training went, discusses upcoming tournaments, that sort of thing.
Training matches with money on the line could be a good way to drive conflict.
Duelist guilds are illegal aren't they?
I would like to see more exclusive religions with convictions that they are the one true faith. That would be fun.
6. Settle elections man to man. Duel the contenders to decide the better man.
That alone is just a duel, but a realm could be run with political parties. Three nobles join together to contend for the government seats with the king appointing the winning party (assuming they're all still alive).
7. Have "keep what you kill" laws in your realm: If a knight kills his Lord he becomes the region lord. If a Lord kills the Duke, he becomes Duke, if someone kills the King... Thus only the STRONG will rule.
I think people would just ignore the duel challenges for the most part. I don't think that would create the sort of factionalization I'm looking for, it'd tend to cause chaos instead.
8. They only won because they were hiding behind lesser men. Anyone who beats you in the field is too much of a wimp to face you alone!
This is supposed to be about intra realm conflicts.
9. Form an infiltrators guild. Nobles can refuse duels, but not stabbers! Then target some poor random Lord and blackmail him for a ransom.
Blackmailing lords will probably just get them arrested, although I can see infiltrators becoming a part of the blood feude.
10. Start a marauder's realm! Whenever you walk into someone's region, blackmail them for a ransom. If they don't pay, maraud the place and then run away to the safety of your fortress.
Again, that can only be accomplished in a foreign realm which wouldn't create an intra realm blood feud, it would just create a regular war. In the past I've seen people who attempt to start wars by looting without orders get shot down pretty quick.