“ Historicly, we have had plenty of rl groups like the Taliban and the Puritans who supressed anything which was in any way fun. What if there was some group that was the opposite? (which in time would cause problems of it's own for the civilians under their control.)”
“ Whilst exploring underground the PCs discover tube like tunnels stretching for miles, upon further inspection the strange tunnels seem to connect all major cities in the are, what is their purpose?”
