Nuclear war, zombie outbreaks, meteor strikes, economic collapse, alien invasion, no matter how it happens an apocalypse makes for a unique and engaging setting to run a campaign in, even for a jaded GM.
Here’s a few quick tips that can make a good zombie or other post apocalypse game a great one, and keep the group coming back (from the dead?) for more.
Orcs record their deeds through symbolic mutilation, scarring and tattoo. Perhaps creating the medium of skin as art, which humans followed later. Perhaps tattoos remind the elves of orcs and make them angry...