Mark Delsing  I don’t know… I haven’t really crystallized any of these thoughts. Now mulling over the Ron Edwards comment you made.

How is it functionally different from the randomly generated event? Well, the only thing I can think of offhand is coherency and the event being linked to a larger chain of events… 

With the random chart, you’d need to think:Why this town? Why now? Why not somewhere else?

I tend to develop these things sort of like PbtA fronts… there’s the necromancer with his orcs… I know his agenda maybe a rough course of action. 

What I could do is put the ‘trigger’ for his invasion on a random table, or link it to the PCs actions, like a PbtA clock… But I have a rough idea of my bad guys and their motives. The list of baddies gets added on to by the PCs actions, or perhaps their agendas get modified, though.