In D&D when does a fight end?
Ask this question and most of the players will tell you "When all foes are dead".
This is because most DMs run every fight till enemies's death.
It's an uncorrect behaviour because nobody fights to death; in dangeours situations everyone look for an escape to save life. It's instinct that leads men and animals to preserve life, so they will parley or runaway if possible.
To escape or to surrender, as well as being realistic, can lead to a interesting new paths of the game:
- where do enemies run?
- will PCs purse them?
- are they leading PCs to a trap?
- are they going to call for aid?
- have they got anything to give to spare their lives, such as...?
- ...precious informations?
- ...wealth or magic items?
- will they become allies of the party?
Once I had a NPC wizard, surrounded by PCs, he bargained his life offering a magic item with the words of activation. After the deal he vanished and the party discovered the item was a fake.
So it's a good and interesting thing to have fights ending in other ways, you must ask another question to yourself:
When do you know they have to flee or to parley?
Older D&D editions had Morale rules: every monster had a value from 1 to 20 assegnato with tables complete of modifiers according to various situations; a roll higher then the value modified have the monster to flee.
In newer editions these rule has vanished but I don't miss it: I can focus on more important things and save time instead of rolling dice and make calculations.
You, as DM, already know what will happen to the foes in their turn.
Just ask yourself:
- are they winning the fight?
- are their allies being killed?
- are they able to hurt the PCs?
- can they flee without being hurt?
- do they have a sanctuary where to go?
- can they make an offer to PCs?
Give quick answers to these questions and you can easily know to continue the fight or make other decisions.