The Duels can be found at Rings of Honor.
The following is an excerpt from the current Rings of Honor Website:
The dueling sports are widely popular in Rhydin. They provide a venue for warriors to polish their combat skills or to settle disputes among one another in a civilized manner. The tides of political power in Rhydin are often dictated by those who control the various titles of these sports.
When your character engages in a duel with another character, you as the player engage in one of three matrix-based games with the other player. The purpose of these games is to enhance the role-play by guiding the action. They also provide a depth of competition nonexistent in dice-rolling games, and as a player you will feel more engaged in the role-play as you try to anticipate the other player’s moves, much like your character will be trying to anticipate the opposing character.