I have a quest to capture a Lord from a certain faction, but they keep escaping after I have taken down their armies. Is there a way to prevent this from happening? Or at least increase the chance that I will be able to capture them?
You may only take prisoner people you have knocked unconcious. You must first take down the Lord, then take down their armies. However, if you take a Lord prisoner he may escape after some time traveling.
Escaping: For every 72 hours the Lord is in your party he has a 50% chance of escaping. If you have a jail in your town, you can put him in their and he only has a 10% chance of escaping
More prisoner management you have, better are chances to capture a lord.
I've found that if you whittle down the enemy army first, then knock out the Lord, his chances of escaping are much lower. I guess because he has no men to "drag him away from the fighting" like your men do for you when you fall in combat.