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.
During battle/war the heads of all slain are decapitated and collected by the slayer. The slayer will clean them up and put them on display for inspection by the commander. Depending on the deads name, rank, and expression on the face held by the death blow-the slayer will be rewarded by gold and/or status.