Books like Key to Havoc by Piers Anthony

A millennium after Earth colonists settled on the planet Charm, the inhabitants have lost advanced technology but gained a strange form of magic tied to volcanic eruptions. Each volcano bestows a distinct color—such as red, blue, or green—upon its surroundings, and any plant, animal, or person within that region assumes both the color and its associated magical power. Havoc, a fierce barbarian from a non‑Chroma village where magic is absent, survives a cruel world by rescuing a dragon that grants him a unique gift: the ability to sense impending danger. Suddenly the assassins of the former king elevate him to rulership, forcing him to balance his newfound authority with the threat of a lethal pursuit. Now, as he faces treason charges if he fails his duties and an assassin’s relentless hunt, Havoc must rely on his dragon‑gift and the complex network of colored magics that define Charm to protect his people and secure his own survival.

First publish date: 2003