Some thoughts: would disarming opponents require a specific skill to be learnt? Perhaps there could be an attack which gad a higher chance of missing and did less damage, but could knock an opponents helmet off. Similarly for knocking an opponents HEAD off. The chance of crushing limbs with blunt weapons, crippling the opponent (reducing his dodge by 1/4 or 1/3?) with normal attacks or critical blows. Slightly off the subject I know.
As it is DD, if you run far enough then the monster chasing you will run back to where it hangs around. A fleeing system wouldn't be too difficult, it would only require the distance and chance to be altered with some monsters. Some could be clever. For instance, if you took up close range combat with a troll, it would suddenly flee after a few seconds. If you chased it then it would turn back and swing with all its might at you, catching you off guard. But if you didn't chase it, it might return and throw rocks at you. Meaning you would have to be more on guard.
I was thinking that perhaps ranged characters could form a line or formation and fire high at you all at once, covering a huge range. Your dodge would reduce the damage somewhat, but you would never be able to entirely avoid it. The same applies for attacking all at once, maybe from different directions.
Speaking of directions, I remember a game called Astonia 3, where if a player was attacked from the behind, their chance to parry or dodge would be greatly reduced. This applied with side on attacks as well I believe, but not so much of a nerf.In Ragnarok Online, your flee is reduced by so much after so many monsters are attacking you. So it is impossible to tank large numbers of monster as a character who focuses on flee unless they are weak.
I think those are good systems. Perhaps something similar could be done with monsters, if not players. If a monster was being attacked by multiple things, then they would flee, if possible. Or they could call for help and all their nearby allies would come to help. Although it is a single player game, you can summon monsters, and there are allied NPCs such as guards in DD.
Sparing an opponents life...they could easily backstab you, or have hidden tools or weapons, or brute strength. Where they are held, what direction you face etc. would depend on these things.
I know that enemies which run away are annoying, but they can also run you into traps. You would have to struggle to survive, and there may even be a special skill or spell cast on you or the enemies.
