Given the size of combats that I can see happening in the near future (sixteen or more PCs and followers vs. ten, twenty, or even thirty monsters at a time), it occurs to me that I should make a point of checking morale more regularly than I've normally done before, so that fights end when a group runs away, rather than dragging on until forty or fifty combatants have been reduced to the last man standing.
The Delving Deeper rules give the GM total discretion as to when to make morale checks for monsters and NPCs. I'll probably do something like this:
- make an individual morale check for a monster or NPC when it drops to half its maximum HP
- make a group morale check every time one member of the group is killed
I'll likely define "group" as "all monsters of a given type" and "all followers of a given PC."
Failing a morale check will have consequences. Charmed NPCs or monsters who fail a morale check make a new saving throw to see if their charm is broken. If the charm breaks, the now un-charmed creature heads for the hills and keeps on running, never to return. Otherwise, fleeing NPCs and monsters, including charmed ones, are affected according to the actual score of the morale throw (a five or less on 2d6 being a morale failure in Delving Deeper):
In addition to normal morale modifiers, each consecutive check in a single combat will be at a cumulative -1 modifier per check previously taken in the fight. And in any case, a natural "2" will always be treated as a 2 regardless of modifiers.
When monsters flee, their noisy, panicked flight will undoubtedly alert other monsters in the area to the PCs' presence, if they weren't alerted already by the noise of the fight.
Results will be adapted to circumstance; e.g. a group won't run if they have no escape path – they'll obviously cower in place or surrender instead.