In many Post-Apocalyptic settings the state of the world is a result of nuclear disaster. Often this is the result of an arms race between two superpowers. Two nations don’t trust each other and they build better and better weapons to use on their adversaries until eventually the whole thing blows up (quite literally most of the time) and both nations along with the rest of the entire world pay the price. Kaverus is similar, but instead of nuclear fallout, the world is suffering a magical fallout. Instead of a nuclear arms race, the two kingdoms had a magical arms race, and as a result the entire world of Kaverus has suffered.
It has been 73 years since The Cataclysm, and Kaverus is still feeling its effects. Mages and sorcerers must practice in secret or suffer fates as dire as lynch mobs or Dragonborn Mage Hunters. While traditional swords and arrows are most common, Blackforge has developed primitive firearms, and you can usually find several people in any given boomtown armed with a Snakebite or Thunderclap rather than an axe or crossbow. Every race has felt the effects of The Cataclysm in one way or another but people have adapted. On Kaverus you find your niche, or else you meet your end.