What This Ruleset Is

This manual is for the people building on the system: the world-builders, the entry-writers, the people who will pour a setting into these containers. Before any of that — the design. If you understand what this ruleset is trying to do, every entry you write will fit without being forced.

The design's spine

Preparation is power. There is no casting. A practitioner's instant effects come only from prepared works — charms, amulets, talismans made ahead of time. The prepared magician is dangerous; the surprised one is a person with salt in their pockets. Every rule in the system exists to make that promise true: crafting takes time, works are consumed or charged, dynamis caps how much spark a day can hold, and a properly prepared working succeeds without a roll. If you build content that lets a practitioner improvise power freely, you are building against the spine.

One grammar, two addressees. Theurgy writes to the gods; goetia writes to the spirits. They share every mechanism — the same roll, the same objects, the same grades — and differ only in who answers and what it costs. Theurgy is slow, sanctioned, permanent, and demands purity. Goetia is fast, unsanctioned, and runs on a ledger of claims that compounds. That tension is the game's identity: the same craft, two doors, and every practitioner chooses where to stand between them.

Two axes, not two moralities. Allegiance (Celestial −10 ↔ Chthonic +10) and purity (miasma 0 → defiled) are the cosmology in two numbers. Neither is good and evil; they are order and appetite. Allegiance decides which school works at full strength and which court answers you. Miasma poisons theurgy, feeds goetia, and at 5+ puts sanctified works to sleep. A world built on this ruleset can rename the courts, but it should keep two dials that pull in opposite directions — the system's drama lives in the pull.

Grades are gates, works are gear. The four Eleusinian grades (Myesis → Mystes → Epoptes → Hierophant) are the vertical axis: grade is the flat bonus on every roll, the gate on every formula, work, and daimon, and the ceiling on the dynamis pool (4 + grade × 2). Nothing above your grade is open to you, however hard you roll. The horizontal axis is collection — formulas, mysteries, works, bound spirits, materials — and it is where most play happens. Rank is the ceiling; the hoard is the game.

What a world must keep

These are the invariants. A world may re-skin everything else, but if one of these breaks, it is no longer this ruleset:

1. The roll grammar — d20 + Stat + Preparation + Grade + Dynamis (≤ +3) − Miasma, vs. a DC. One resolution rule for everything.
2. The preparation promise — Complete preparation at leisure succeeds without a roll; instant power comes from prepared works.
3. The dynamis cap — a small daily pool that never banks and cannot be bought. The throttle on all power.
4. The two-school tension — two addressees with opposite economies (grace vs. ledger), and a cost for the middle.
5. Grade gates — nothing above the practitioner's grade, ever. Power grows slowly and structurally.
6. The failure ladder — failures cost something and reveal something; twisted results are how curses are born.

What a world may re-skin

Everything else: the gods and daimones (deity and daimon files), the formulas and mysteries (mystery files), the material tiers and their names, the spheres of the trials, the names of the grades, the flavor of the seven planetary spheres, the location and item catalogs, the tone. The ruleset is the engine; the world is the paint. This manual's job is to keep the engine running while you repaint it.

The rest of the chapters: the toolbelt (what each file type is for), the numbers (how the engine measures), extending (how to add to the ruleset safely), building a world on top (the playbook), and voice (the conventions that keep it all coherent).