What caused your apocalypse Veeky Forums?
End of the World
the PCs, of course
I had two That Guys. One sparked a civil war, the other blew a hole in reality.
I kicked them out, and am now running a post-apocalyptic fantasy game and Those Guys' characters are demonized worse than Fantasy-Hitler.
smugness level: astronomical
NoooOOObody knoooooOoooows!
Zargothrax, the Dark Sorcerer of Auchtermuchty.
A serious lack of nukes.
No nukes, no Cold War. Just one big, hot one.
Ideological struggle.
The people living in the world now don't even know they're living in a post-apocalypse world.
Wizards experimenting with daemon magic ripping a hole into the dungeon dimensions
Climate cataclysm. The world is now pretty much Mad Max without the gimp raiders.
How did the other guy blow a hole in reality?
What ideologies?
A a really weak gamma burst.
Not strong enough to kill of all of humamity, just enough strength to kill of technology and give all of humanity super cancer.