Sjórseiðr · Storyteller · GM Reference

Integrating a New Magic System into Hermetic Theory

The Original Research → Breakthrough → Integration track — how a covenant magus turns folk magic (or any non-Hermetic tradition) into something the Order can learn.

Prep reference for the plans tracked as t019 (Wilhelm's folk-magic "pocket" system), q017 (learning new folk-magic guidelines), and tl025 (how Magic Theory is created from scratch). Everything in the boxed passages below is reproduced verbatim from the rules; the connecting text and the applied notes are the GM's own framing.

The shape of it, in one breath

A magus cannot simply "learn" a rival tradition. To bring a non-Hermetic practice inside Hermetic magic he mounts a research project that accumulates breakthrough points until it crosses a threshold. Points come from two engines — blind experimentation, and studying the foreign magic for insight (the Integration path) — and the two can be mixed in a single project. When the threshold is reached, the discovery is stabilized (paying Warping), and only then can it be taught to other magi, usually as Supernatural Virtues.

Step 1 · Decide the size of the Breakthrough

The troupe must define the intended result in advance and agree on its scale. Folk magic is explicitly a Major Breakthrough — the rules name it directly.

Minor

~30 points

A new Range, Target, or Duration — adds to existing theory without reaching the Limits of Magic.

Major

~45 points

Pushes the limits without breaking them. Incorporating hedge magic is a Major Breakthrough, taught onward as Supernatural Virtues.

Hermetic

~60 points

Breaks a Lesser Limit of Magic (e.g. a new Arcane Ability). Once in 450 years: Bonisagus's Parma.

Step 2a · Earn points by Experimentation (Original Research)

Invent an ordinary Hermetic spell or lesser/charged enchantment that somehow embodies the idea, then experiment on it. You are fishing for the Discovery result on the Extraordinary Results Chart; the trick is that your risk modifier is spent nudging that roll rather than your Lab Total. Magic Theory caps the modifier: +1 per 5 Magic Theory, so +2 needs MT 6, +3 needs MT 11.

Step 2b · Earn points by Integration (Insight)

The path most relevant to a covenant sitting on stacks of hedge-wizard material. Study a text, a relic, or a living/ghostly teacher of the tradition. Each season: a stress roll of Int + Magic Theory vs. Ease Factor 18 (Inventive Genius adds 3). Success yields one insight; a botch is a false insight that only reveals itself when the effect turns out entirely Hermetic or inert.

Step 3 · Cash each insight in — "Creating the Effect"

An insight doesn't hand you points directly; it lets you invent one specific effect (chosen by the troupe, at a fixed level you may not yet be able to reach). Invent it — experimenting as you go — and banking succeeds: you gain breakthrough points equal to the effect's magnitude, then must find a fresh source of insight before repeating.

Step 4 · Stabilize the discovery (the Warping bill)

Points earned from the experimentation engine aren't banked until you stabilize — repeat the exact experiment (same seasons, Lab Total, risk modifier, vis) without rolling a harmful result. Success banks 1 point per magnitude and writes a Lab Text — but stabilizing always costs Warping (magnitude − a simple die), win or lose. Higher-magnitude work reaches the Breakthrough faster but courts Wizard's Twilight.

Step 5 · After the Breakthrough — making it teachable

Crossing the threshold gives the researcher the result immediately (no Initiation needed for himself). But spreading a Major Breakthrough is deliberately hard: it must be taught directly — a new Ability seeded from the converted points, or a new Virtue passed on via an Initiation Script or to an apprentice. Full, free access for any magus requires a second Major Breakthrough to finish the integration.

Applied to Sjórseiðr — Wilhelm & Dustin

Wilhelm's "pocket" folk-magic system (t019) is, in these rules' own words, a Major Breakthrough (~45 points): "Incorporating hedge magic into Hermetic theory is a Major Breakthrough… taught to others as Supernatural Virtues." His stated roadmap maps cleanly onto the Integration engine:

Mine Hermetic texts / send assistants to Ireland → gathering sources of insight (texts, relics, teachers). Each source = one Int + Magic Theory vs. 18 roll for one insight.
Turn that into actual Insight, ideally ceremonial spells folk wizards can learn → the Creating the Effect loop; each banked effect gives points equal to its magnitude.
Fold results back into the folk-magic system (formulaic casting, ceremonial casting, props) → these are the defined results the troupe agrees on up front, delivered as Supernatural Virtues once the ~45 points land and the discovery is stabilized.

Two GM decisions this surfaces: (1) whether Wilhelm's tradition is treated under Hedge Magic Revised Edition / Ancient Magic (both named in the rules as containing ready-made Breakthroughs to lift) or improvised at the table; and (2) the q017 question — "does a further guideline in a branch you're already initiated into get easier?" — is not answered by core: folk/hedge guideline progression lives in the supplements plus your house ruling, and sits outside this core Integration track.

Dustin (Bonisagus, Puissant Magic Theory) is unusually well-suited to be the one who stabilizes and teaches: the risk-modifier cap counts Puissant Magic Theory, and his Inventive Genius adds +3 to insight rolls. For tl025 ("how is Magic Theory created from scratch"): the Ability itself advances normally, but a whole new system entering the theory books is precisely this Breakthrough process — points converted into a new Ability/Virtue per "After the Breakthrough."

GM reference · rules verbatim from the Ars Magica 5th ed. corpus (armdef, Laboratory chapter), fetched at runtime from rules.json · framing and applied notes are the Storyteller's. Cross-refs: Hedge Magic Revised Edition, Ancient Magic (non-core, not reproduced here).