Stones that have been attuned to the extreme temperatures of deserts or icy wastes. Such stones are quite valuable to adventurers as they can use them in order to preserve or prepare meals, make extreme environments bearable, and use them in clever devices.
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.
When a miracle is worked, when a God turns His attention to the mortal realm, the mortal realm is irrevocably changed by the Divine Presence. When this takes place through a living being, they become the Godmarked. Ever with one foot in life, and one foot in the realm beyond, they are emotionally and physically altered - always in a fashion that reflects the nature of the God that they have channeled - One who channels a God of the Winds may forever have a breeze lifting their hair, while a Goddess of Anger may blacken the skin and strengthen the body.