Sometimes when you enter battle with an enemy party that has a notable lord in it, they will offer to duel. (Or sometimes you can offer to duel).
You may accept or decline. Declining will decrease your renown.
Winning the duel will force about 25% of enemy troops to flee immediately. Losing the duel will do the same to your troops.
Method:
1. Ride to the dueling area between the two armies.
2. Look for your faction banner/flag near the dueling area.
3. Ride/walk on top of it, and then select the general that you want to send out to duel. (If you do not do this, you will encounter the duel wait error.) You may choose yourself to duel, but this makes commanding troops immediately after the duel difficult.
4. The duel will start immediately. When one general falls, then everyone will charge. Positioning your own troops tactically immediately after dueling is recommended.
If you are not dueling but enter the duel area, a timer will start. Once the timer counts down to zero, your side will automatically lose the duel (since it will count as you having interfered) and you lose a small amount of renown. If you manage to shoot the enemy general with a ranged weapon from outside the duel area, the same will occur except you lose 25 renown.
this feature is very cool i wish more mods had this