If a crowd of people in a confined space panic and rush in a single direction through a PC's space, what is the effect on the PC? Is there damage and a save? Is it a swarm effect for 1d6 damage? Is it a bull rush? A trip attack?
A mess of overruns?
I know, right? But why would you not just let them pass through your space? How would the danger of such stampedes get modeled?
I think I've seen them done as Xd6 damage, reflex save for half, or intimidate for half (don't remember the DC), or a couple of other things.
I think in the first book of Plunder and Peril (Rum Punch) they have this as part of a chase scene, but i'm at work and can't check right now.
There are no rules for this, only ones for specific scenarios. And those often conflict because the authors want to set a different scene with a panicking crowd.
Plunder and Peril does have it on pages 7-9. It's a low DC of either intimidate or reflex.
Are there any other APs or modules that have this dynamic? If there's nothing official, I can cobble together something from the examples in their adventures.
I would use the base mechanics of Summon Stampede spell.
However, compared to aurochs, humans are smaller, slower and have no special abilities to trample their enemies. Because of that the damage should be lower, and Reflex save check easier.
Maybe the troop template with improved overrun as a bonus feat?
There really ought to be rules for this. I couldn't find any rules at all, but this spell comes kinda-sorta close.
Summon Stampede
School conjuration (summoning); Level cleric/oracle 6, druid 6, summoner 4
CASTING
Casting Time 1 round
Components V, S, M (piece of fur from a herd animal)EFFECT
Range medium (100 ft. + 10 ft./level)
Effect 20-ft.-radius herd of animals
Duration 1 round/level
Saving Throw Reflex halves (see text); Spell Resistance noDESCRIPTION
You conjure a herd of aurochs or similar herd animal that immediately stampedes in the direction you indicate. The herd takes up a 20-foot-radius space and moves at a rate of 120 feet per round in a straight line. Any creatures caught in the herd’s path take 4d6+9 points of damage that round as they are trampled beneath dozens of animals’ hooves. A successful Reflex save halves this damage.
If the stampede’s path would put it in an obviously dangerous area (such as over a cliff or through a fire) or force it to move through a solid barrier, the herd stops at the obstacle and moves in a new randomly determined direction until it reaches another obstacle or the spell’s duration ends.
I imagine that some sort of ad hoc rule could be created for a crowd of medium/large sized creatures based on this spell. /shrug
If it is just a bunch of medium-sized creatures, I'd probably say make 1 Overrun check against the PC with a +2 or +4 circumstance bonus or have the PC make a Reflex save with a -2 or -4 Circumstance disadvantage, if you fail, take 1d6 non-lethal damage. Or something like that.
I think I'm going to use Intimidate or Acrobatics check to avoid being pushed 30' by the crowd in the direction they are going and taking nonlethal damage, maybe 2d6, as in the troop template.