The Numbers

The engine is small — one formula, a handful of tables — and everything else is content written against it. Learn the shapes and you can write entries that measure correctly without ever opening a spreadsheet.

The one formula

d20 + Stat + Preparation + Grade + Dynamis (optional, ≤ +3) − Miasma (theurgy only) vs. DC

• Stat: Wisdom (theurgy), Charisma (goetia), Intelligence (formula craft)
• Preparation: +4 Complete / +2 Adequate / +0 Rushed (or −2 if reckless)
• Grade: 1–4, the flat practitioner rank
• Dynamis: spend up to +3 per roll, and a working costs its grade in dynamis to attempt
• Miasma: −1 per point on theurgic checks only

The DC bands are fixed:

Write effects against the bands. If you describe a formula as "minor," it resolves at DC 10; if you call it "a working that holds a bridge against a siege," that is major, DC 20 — and a grade-1 initiate has no business attempting it reliably. Your prose should be legible against the table.

The preparation promise, quantified

At Complete preparation, at leisure, with nothing interfering: no roll — it succeeds. The roll appears under improvisation, contest, hostility, or high stakes. Two consequences for entry-writers:

• A crafted work, properly made, does its normal job. Its effect should not require a roll when deployed normally — the roll is for the unusual use.
• risk and the failure ladder are what make rushed work dramatic: failures cost something (materials, miasma, the twisted result) and reveal something (an omen, a grudge). Every entry with a roll attached needs a failure mode worth rolling for.

Dynamis: the throttle

Pool = 4 + grade × 2 — 6, 8, 10, 12. It never banks; it refills at dawn (celestial-leaning), moonrise (chthonic-leaning), or half at each (the middle). Burning caps at +3 per roll; a work's seal costs grade × 2 extra; a working costs its grade to attempt.

Write costs in dynamis and materials, not gold. The economy's top end is deliberately closed to money: rare materials are found, extraordinary materials are quests. A formula that costs "1000 gp" is a cheat; one that costs "a rare material and its grade in spark" is the system working.

Grade gates

Nothing above your grade: no formula, work, daimon, or mystery. This is the single most important constraint for calibration:

• Daimon grade = minimum grade to bind → resistance minor 12 / notable 16 / great 20+. A grade-1 daimon should be bindable by a grade-1 initiate; a grade-4 daimon is a campaign.
• Work grade = minimum grade to craft. Its effect's ceiling should match: a grade-1 phylakterion wards a threshold; a grade-4 ensouled work redirects a river.
• Mystery grade = minimum grade to learn and use. A mystery is a broken rule, so its grade is how dangerous the broken rule is.

The rule of thumb: an entry's grade is the smallest practitioner who can use it and survive the attempt.

The failure ladder

Twisted results are how curses enter the world. When you write a risk, aim it at the ladder: a risk that only "nothing happens" is a wasted risk; a risk that inverts, marks, or binds is a story.

Writing numbers that fit

Three checks before any entry ships:

1. The band test — does the effect's size match its DC band? (minor 10 / meaningful 15 / major 20 / extraordinary 25+)
2. The gate test — is the entry's grade ≤ what the story intends, and does its effect belong at that grade?
3. The cost test — does it pay in dynamis, materials, time, or favor — not in gold? Extraordinary costs cannot be bought.

A set of entries that pass all three for the same world will measure against each other automatically. That is the whole trick of calibration: the engine is small, so consistency is cheap.