UselessTriviaMan
Explorer
And this is why I posed the question to this forum. 
I'm intimately familiar with 3.5E, but not quite so much with Pathfinder. Reading the RAW I knew there really isn't any way for the victim to avoid falling, but the Climb check to catch yourself does make sense. (Aside: All PC/combatants in this event are only 5th level, which means that even if they DO catch themselves they're still probably completely screwed. But that's kinda the point.) As I read it, it would be a DC 20 Climb check to grab the edge of the pit. Unless the bull rush shoved them into the center, in which case it'd be... a DC 25? 30? Something like that.

I'm intimately familiar with 3.5E, but not quite so much with Pathfinder. Reading the RAW I knew there really isn't any way for the victim to avoid falling, but the Climb check to catch yourself does make sense. (Aside: All PC/combatants in this event are only 5th level, which means that even if they DO catch themselves they're still probably completely screwed. But that's kinda the point.) As I read it, it would be a DC 20 Climb check to grab the edge of the pit. Unless the bull rush shoved them into the center, in which case it'd be... a DC 25? 30? Something like that.