Modern Deepfire is a divided city. The crater has long since been filled with buildings, and the edge of it marks the formal boundary of the Republic. Beyond that, the mountain is riddled with tunnels, and the people who live in them are called tunnelborn. Tunnelborn are not Republic citizens, and manufactories set up to exploit their cheap labor have become the city’s second primary industry. Tension between the tunnelborn and the Republic citizens living aboveground is common, exacerbated by the plentiful opportunities for smuggling and corruption available to Republic officials.

deiat—the power of creation, identified with the fire of the sun. The Chosen could draw energy from deiat to accomplish a wide range of spectacular feats, from destructive manifestations like balls of flame or bursts of raw force to defensive barriers and more. It could also be used to create unnatural substances, like the indestructible unmetal. More advanced uses of deiat required specialized tools, now called arcana. These devices, when powered by a deiat wielder, could accomplish wonders—the Gates that wove the Empire together and the skyships and skyfortresses that hovered overhead are notable examples, in addition to more mundane tools like blasters, watch charms, water treatment facilities, and so on.

Deiat does have limits. It manipulates physical objects and properties—force, temperature, and so on—and does not interact with biological systems at any level except the crudely destructive. Deiat tools also require a continuous flow of power, either from a wielder or a storage device like a sunsplinter, and cannot operate without the will of the wielder. In particular, the autonomous constructs used by the ghouls are impossible to create with deiat.

With the Chosen wiped out by the Plague, the only wielders of deiat remaining are the centarchs of the Twilight Order, who can use their haken—themselves a deiat-created tool—to draw deiat power, though more weakly than the Chosen could. Why some humans have the ability to wield deiat and others do not is unknown. Centarchs are typically limited to a particular class of effects—fire, ice, force, and so on—although all can use deiat to power arcana such as Gates and panoply belts. Only the most primitive of construction techniques are still known, but existing unmetal can be reforged and reshaped, allowing the creation of the armor of the centarchs and the Legions.

dhak—Originally, this term referred only to ghoul arcana produced using dhaka. In the centuries since the Plague War, its meaning has expanded and is now synonymous with unsanctioned arcana—arcana not in the very narrow categories approved for safe use by the Twilight Order. Possession of dhak is illegal in the Dawn Republic and grounds for immediate imprisonment or even execution, at the discretion of the arresting official.