When I talked about the d30 Sandbox Companion last night with my gaming group, one of the tables that elicited a "hot damn!" of excitement was the Cult Generator on page 21.
It has five columns, the first two help supply the name of the cult, and the last three cover worship, immediate goal and strange practices.
Let's try to randomly roll out two cults (remember, this is more to seed your imagination than anything else - it's barebones and needs to be fleshed out for gameplay):
Rolls of 21 and 22 for columns 1 and 2 gives us "The Partnership of the Smoke".
A roll of 17 indicates the worship / following of a male elfin magic-user. Hmmm, make that elf a drow and the "smoke" could refer to the hair. Or maybe he specializes in wall of fog and cloudkill like spells.
A roll of 16 for "immediate goals" results in a cult that seeks the destruction of libraries and books. Maybe this is a cover for the cult leader - maybe he is looking for certain magical books and is seeking to destroy the others as a distraction.
Finally, the last roll is a 13 - these kooks never cut their hair.
Rolls of 4 and 11 for columns 1 and 2 gives us "The Church of the Elect".
A Roll of 1 indicates they worship a beholder. There's no way this could be anything but a death cult ;)
Another roll of 1 gives their immediate goal as anarchy. See, told you this shit was bad...
Finally, a roll of 21 indicates that they sleep from hooks. This is the type of cult the PCs best run from or destroy outright, because they are crazy enough to be truly dangerous and they have a beholder pulling their strings.
Damn, this shit is fun and supplies some damn good hooks for my current sandbox. Further details would be needed to run with this if it were to be more than background noise in the campaign, but as my players do read the blog, I'll leave them as is for now ;)
Just think, over 24 million cultish variations from one table...