House Rules

This page will have all the house rules (and, in some cases, clarifications of Rules As Written) that are in effect for the saga. I'm going to try to keep the number of house rules to a minimum, but these are the ones that in place so far. Any future house rules will be discussed in the forums before being finalized here.

Rule Number One

When I say run, run.

The Doctor lies.

K.I.S.S.: Keep It Simple, Sodalis. There are a lot of books out there (43 currently listed on Project Redcap, although I think they're pretty much done making 5th edition books…we'll see how things go if they ever make a 6th edition). I don't expect anyone to have and use all of them…I know I sure don't. So. Unless otherwise decided:

  • Any rules in the Main Rulebook take precedence over any contradictory rules in any of the other books.
  • Any rules from the Houses of Hermes books or Covenants that don't contradict rules from the MRB take precedence over rules in any of the other books.
  • Any character generation or advancement rules from Apprentices or Grogs that don't contradict the MRB will be in effect.
  • Any rules from any of the other books should be discussed before adopted. When in doubt, I will go with streamlining and trying to avoid "rules creep."

Ability Specializations

Two things of note about Abilities and their Specializations.

  1. When you create your character, you should have a Specialization for each Ability. The Storyguide knows how hard that is to do, sometimes. Therefore, if you cannot come up with a Specialization for every Ability at character creation, you may leave some blank. The first time you use a Specialization for that Ability, that effectively locks it in (but see below). This House Rule should not be abused, and not all of a character's Abilities' Specializations may be left "to be determined" in this manner.
  2. A Specialization may be changed (in a reasonable manner) any time you increase the Score in that Ability. For example, if you have Hunt ''(rabbits)'' 3, but you spend a lot of time tracking larger animals, then you may change your Specialization to "(tracking)" when you increase the Ability's score to 4.


  • Experience Points gained in Adventure may be spent without forfeiting experience/advancement totals (e.g. from Study, Teaching, or Training), barring Distraction Penalties. So, if you were Training with the turb, for example, and went on an adventure that lasted five days and gained you 8 xp, you could spend those 8xp normally on things you used (or tried to use) during the adventure, and get the full advantage of the sergeant's SQ for learning Single Weapon.
  • You always gain 2 xp per season for Exposure to the local native language (in this case, Gaelic), unless you gain Exposure from another source (such as lab work), in which case you can use Exposure for one or the other. There may be cases where you're somewhere where Gaelic isn't the native language (such as Stonehenge or Normandy) for a whole season, in which case you could take Exposure xp for the local language. This rule is only in effect if your score in said language is less than 5; once your score is 5 (or better), you have a native proficiency and no longer benefit from Exposure.
  • Familiars Only: Due to the nature of their Bond with their maga, a Familiar with a Might Score does not take the penalties to advancement that Magical characters normally suffer (Realms of Power: Magic, p. 52).

Aegis of the Hearth

  • Aegis of the Hearth, being not entirely Hermetic in nature, does not adhere to the base individual size for Boundary listed in the rulebook. And unlike other T: Boundary spells, the boundary must be defined by the caster during the casting of the spell, by walking the defining boundary. Note that, depending on the actual size of the Boundary, this may result in the spell taking longer (but not shorter) to cast than would be indicated by the spell level.
  • The Aegis must penetrate for the warding effect, but does not need to penetrate for any of its other effects (e.g. to affect casting totals or magical abilities).

Approaching the Boundary of an Aegis of the Hearth

The description of Aegis of the Hearth says that "when approaching the border of an Aegis, a…Hermetic magus feels a slight tingle in the extremities." This is most commonly interpreted to mean when you touch the border, cross into an Aegis, or are in an area protected by an Aegis.

In this saga, the maga feels the tingle when she's approaching the border. When she approaches within (the square root of the Magnitude) paces, she feels a tingle. Once she crosses into the Aegis, she no longer feels the tingle. If she were to Seven League Stride through an Aegis for which she does not have a Casting Token (and successfully Penetrates said Aegis), she will feel a brief tingle at the end of the transit but not when she appears at her destination.

For example, when approaching the weakest possible Aegis (level 20), she feels the tingle at two paces. If a covenant had a Level 45 Aegis, a magus would feel the tingle at three paces.

Bonisagus House Acclaim

Per Houses of Hermes, True Lineages (p. 21), "Reputation spreads by word of mouth, a slow process in the Middle Ages. Typically it takes a year per gained Acclaim point for the reputation to spread."

Your House Acclaim spreads faster, the closer you are to home. In your own covenant, you get to take advantage of the Acclaim Points right away. In Loch Leglean, it spreads at 2 points per year. In Hibernia and Stonehenge, it spreads at 1½ points per year. On the continent, it spreads at the default 1 point per year.

Example: Alistair has 16 House Acclaim Points. If he were a resident of Insula Canaria, for Boudicca he would have a House Acclaim Score of 2. For Argentius, it will take him eight years to reach that score. For Milvia or Maximianus (of Hibernia and Stonehenge, respectively), it would take him ten years to reach a score of 2.

Bjornaer Apprenticeship

Bjornaer Apprentices, once they've undergone the Ritual of Twelve Years, do not necessarily have to be trained by a Bjornaer magus whose Heartbeast has the same Temperament as that of the Apprentice. It is only necessary that the one be suited for the other. For example, a magus with a Fox heartbeast could train an Otter Heartbeast, but not a Mole.

Casting Requisites for Rego Corpus spells

Spells that use the Arts of Rego and Corpus (or Animal) to apparate from one place to another do not necessarily require casting requisites. As a rule of thumb, anything that would be covered under the casting magus's Parma Magica and does not have a Load score does not need requisites. This is typically the magus, anything he's wearing, and his Talisman.

Anything that is carried (aside from his Talisman) invokes Casting Requisites if it has a Load score or is a separate Corpus or Animal Individual (or Group). Thus, a cat or a very small child requires a Requisite (although, in truth, carrying a small child would probably require a T: Group version of the appropriate spell.)

Casting Tablets

Due to an idiosyncrasy of Hermetic magic, Casting Tablets (Covenants, p. 89-90) can only be created for Ritual spells. Hermetic magic has yet to find a way to bind the spell's power to the tablet for lesser (i.e. Formulaic or Spontaneous) spells. Note that, despite the name, a "Casting Tablet" is not, in fact, a stone tablet à la the stone tablets handed down on Mount Sinai, but can be scribed on anything that a lab text can be.

Also note that a Casting Tablet does not have Penetration unless you purchase additional levels. For example, casting a Level 30 Aegis of the Hearth from a Level 30 Casting Tablet has 0 Penetration, regardless of the author's or caster's Casting Total. Casting a Level 30 Aegis of the Hearth from a Level 50 Casting Tablet has 20 Penetration, but costs as much as a Level 50 Laboratory Text (i.e. 20 Build Points).

Faerie Magic

Taking the Virtue Faerie Magic (MRB, p. 92) confers the Ability Faerie Magic (Houses of Hermes: Mystery Cults, p. 88) with a Score of 1 (as is the case with every other Virtue that confers an Ability).

Fixing Arcane Connections

It takes one week for every step removed from Indefinite that the Arcane Connection is at the beginning, and you must have a ReVi lab total of three times the number of steps. Thus, to take a bottle of water from a moving stream and use it to fix an AC to the stream would take six weeks and you must have a ReVi lab total of 18. To fix an Arcane Connection from a strand of a character's hair would take three weeks and require an ReVi LT of 9. As per Rules As Written, once you begin the process of fixing the Arcane Connection, it does not decay so long as you continue the process. If, for whatever reason, the process is interrupted or suspended, then the Arcane Connection begins to decay again. (This would only be a problem for those Arcane Connections that last hours or days.)

It still takes one pawn of Vim vis (as with RaW).

Inventive Genius

Inventive Genius (p. 44, MRB) applies to more than just inventing new spells, crafting magic items, and making potions (e.g. Charged Items). It applies to most Lab Activities that involve a Lab Total.

Activities that receive the +3/+6 Bonus from Inventive Genius include:

  • Inventing a spell (including using a Lab Text).
  • Enchanting an item (whether Invested Device, Lesser Device, Charged Item, or Talisman).
  • Inventing a Longevity Ritual.

Activities that do not receive the Inventive Genius Bonus:

  • Learning a spell from another magus.
  • Preparing an item for enchantment.
  • Attuning or increasing the vis capacity of a Talisman.
  • Create Figurine (using Figurine Magic).
  • Binding or empowering a familiar.
  • Vis extraction.
  • Setting up or improving a Laboratory.

Lab Creation and Customization

STRUCTURES: In general, can be taken for no BP/time cost if the virtue or flaw is intrinsic to the lab's location.

  • Greater/Lesser Feature: can also be free when taken with the Greater/Lesser Focus flaw, where the Focus and Feature are the same object; otherwise, requires time and BPs to invest.
  • Natural Environment: free only when taken with the Outdoor flaw; otherwise, requires time and BPs to invest.

OUTFITTINGS: In general, always requires BP, time, and silver.

  • Excessive Heating, Excessive Lighting, Living Quarters, Superior Heating, Superior Lighting can be taken free.
  • Assistant, Guard, Person, Servant are free only if those roles are filled by an established character (i.e. a fully statted character with an entry on the Wiki).
  • Precious Ingredients, Priceless Ingredients require significant initial investment in silver.
  • Superior Equipment / Superior Tools are free only when the relevant craftsman is available.

SUPERNATURAL: In general, this always requires a story, which means they can only be gained in play.

  • Greater/Lesser Guardian and Greater/Lesser Horde are available free only with story set-up, e.g. a Magical Animal Companion can be a lab's Guardian (though the companion may resent being treated as an asset rather than a friend); a Horde would be free if a magus has a Pack Leader for a familiar.
  • Familiar: free if you have a familiar.
  • Gateway, Vis Source, Ice Cavern, Regio, Shrouded, Site of Legend; all the minor and free supernatural flaws: all can be free depending on where the magus chooses to build their laboratory. Note that not all of these options will necessarily be available, and note that paying BPs for the virtues in question does not buy the object/location in question if it does not already exist.
  • Flawless Equipment: Free only when the means of magical creation are secured.
  • Faerie/Magical Ingredients, Inexhaustible Supplies, Preserved, Sentient: must be acquired in play.
  • Enchantment, Invisible, Magic Item, Magical Heating/Lighting, Relocation, Shrouded; Greater Illusion, Mental Construct : all can be free if the magus invests these effects.

Language Scores and Books

You need to have a Language Score of 4 and an Artes Liberales Score (with literacy in the script in question) to be able to read a book in a given language and benefit (i.e. get xp from it); with a Language of 3 or less, you can still read it (as long as you have the Language and the Artes Liberales), but you don't understand it well enough to get the benefit. Most books in the Order are in Latin, but there are likely to be a few books floating around the Tribunal in Gaelic.

You must have a Language Ability score of 5 to be able to write anything with a Source Quality (such as summae and tractatus). To simply write letters or whatever, you simply need the Artes Liberales and literacy in the appropriate script. Note, however, that with a Language of 1, it's going to wind up looking like the letter I just got from my six-year-old cousin.

An appropriate Specialization in the Language in question does apply when figuring the Ability Score. For example, if you have Latin 4, with a Specialization in Hermetic Terminology, that gives you a de facto score of 5 and can write a book.

This interpretation stems from the Storyguide's observation that practically none of the published characters (including members of House Bonisagus) would be able to write books if this were not the case, and at least a couple are of an age and description that indicated that they had done so.

Learning a Magus's Shorthand

In addition to deciphering a magus's shorthand himself ("Translating Laboratory Texts", Ars Magica 5th Edition p. 102), a magus may also teach another magus (or apprentice) the secrets and abbreviations he uses in his laboratory texts. This is a seasonal teaching activity. Upon completion, the student may translate the teacher's laboratory texts up to a level determined as follows: Teacher's Int + Magic Theory + highest Technique score + highest Form score + modifiers from Virtues and Flaws (both the teacher's and the student's), and not counting any bonuses or penalties from the laboratory being used. For example, if the teacher's Laboratory has a Corpus bonus of +3, he does not add that to the score used to determine the student's translating limit.

Longevity Rituals

  • It takes a full season to invent a magus's (or mundane's) Longevity Ritual. It is usually assumed that the ritual is performed once invented. However, this is not necessarily the case. A Longevity Ritual may be invented and performed at a later date (whether for personal reasons, lack of vis, etc.).
  • Any time a Longevity Ritual is performed without having been newly invented, it takes as much time as a Ritual Spell of the same level as the Lab Total. For example, a Longevity Ritual Lab Total of 56 would take as long as a 12th Magnitude Ritual Spell – namely, three hours.
  • Performing a new Longevity Ritual once your old one has failed (generally due to an Aging Crisis) does not mitigate the effects of the Aging Crisis. If the Crisis Table results in "Bedridden for a week," then whether you re-perform your Longevity Ritual or not, you're still bedridden for a week during that season.
  • Confidence cannot be spent on an Aging or an Aging Crisis roll.

Lore and Knowledge Abilities

Attempts to use a Lore (Area Lore, Organization Lore, etc) and Knowledge Abilities always use a Stress Die. This is because the character typically does not have time to try again if the first attempt goes badly.

Major and Minor Flaws for Grogs

At character creation Grogs may take a Major Flaw and/or a Major Virtue, so long as they do not have more points in Virtues than they do Flaws.

Performing a Parma Magica ritual in a hostile Aegis of the Hearth

Ordinarily, a magus must simply take two minutes to perform his Parma Magica ritual, regardless (even in a Dominion or Infernal Aura).

However, if he attempts to perform his ritual in a "hostile" Aegis (an Aegis of the Hearth in which he did not participate in the casting and into which he has not been invited), he must must roll Sta + Parma Magica vs. an Ease Factor of (3 + the Magnitude of the Aegis) for it to succeed. Under most circumstances, you can just try and try again (i.e. a Simple Die, or hand-waved), but there are times when you can't (i.e. a Stress Die, with only one Botch Die).

A botch on this roll does not carry the risk of Twilight.

Also note that entering a foreign Aegis does not affect a magus's Parma Magica. He merely suffers the penalties to spell-casting and certain Supernatural Abilities as defined in the rulebook; his Parma Magica is not dispelled if he enters a foreign Aegis or has his permission revoked.

Personality Flaws

At character generation, a character may take up to two Personality Flaws. If they do take two Personality Flaws, only one may be Major.

Renewing Long-Lasting Spells

Any spell that has a set duration longer than Momentary (i.e. Sun, Moon, or Year) has a certain "buffer period" when the spell must be recast for its effects to be continued. This period is a diameter (two minutes) or the length of time it took to cast the spell, whichever is longer. Normally, the spell expires the minute the duration ends. If a replacement spell is started within that buffer period, however, the spell does not expire until the new spell is cast; if the replacement's spell's casting is interrupted for any reason after the original spell would have ended, the spell ends at that time.

  • Example: a Level 30 Aegis of the Hearth, cast on 14 December, 1219, would expire at 4:21 am on 14 December, 1220. A 6th Magnitude Ritual spell takes 90 minutes to cast; therefore, if the covenant begins to cast a new Aegis of the Hearth any time between 2:51 am and 4:21 am that day, then the new spell's casting will effective prop up the previous Aegis until the new spell's casting is complete. If the maga casting the spell stumbles and falls at 4:25 am, before the spell is cast, then the previous year's Aegis will collapse, and the covenant will be unprotected until the Aegis can be cast.

This also applies to Parma Magica. There is a two-minute buffer before sunrise in which the magus can begin to perform his ritual; so long as he begins his Ritual within two minutes before sunrise and is not interrupted, his protection will not lapse. It would only be if he can't perform his ritual that he would lose his protection. As the ritual is completely undefined, the magus would have to be totally immobilized (or unconscious or asleep) for him to be unable to perform his Parma Magica ritual.

Ritual Spells and Die Type

Under the Rules as Written, a Ritual Spell uses a Stress Die at all times. This results in an extraordinarily high probability of Botch under most circumstances, unless the caster has a large number of levels of Spell Mastery, a Golden Cord bond with his Familiar, or other means of reducing the number of Botch Dice.

Therefore, the Saga has adopted a House Rule that under most circumstances, Ritual Spells are cast using a Quality Die and not a normal Stress Die. A Stress Die is only required under actual stressful situations, such as casting a Healing ritual during a battle or trying to cast an Aegis of the Hearth before the demons arrive.

The vast majority of the time, Ritual Spells will be cast in a "calm situation." Aegis of the Hearth (under normal circumstances), Creo Corpus Healing rituals, etc. There are times, however, that even Rituals may be cast in Stressful Situations. If it looks like a Ritual may be going to be cast in a situation that may potentially result in Botch Dice, the Storyguide will let the player(s) know.


Any time that a result is divided (such as halving when casting spontaneous spells) or multiplied (such as experience subject to Affinity), round to the nearest whole number. If the remainder is exactly ½, then round away from zero (for example, 3½ rounds to 4, and -6½ rounds to -7).


The Hermetic year begins on the Spring Equinox (usually 13 March, but sometimes 14 March). Spring is the first Season of the Hermetic Year, and it progresses through Summer, Autumn, and Winter. (When needed, the exact date and/or time of an Equinox or Solstice is found using the Stellafane Equinox & Solstice Calculator, with the times set to UTC.)

Starting Spell Levels

According to Ars Magica 5th Edition, the highest level spell a wizard can learn at character creation is equal to Technique + Form + Intelligence + Magic Theory +3 (p. 32, and the insert on p. 29 for Detailed Character Creation Summary). This formula is identical to that used for inventing spells, given that 3 is the "default" char-gen covenant aura.

This saga has determined that Virtues and Flaws that affect a character's Lab Total when inventing spells also affect the maximum spell level one can have during character creation. These Virtues and Flaws are:

  • Adept Laboratory Student (AM5, p. 40)
  • Inventive Genius (AM5, p. 44)
  • Major Magical Focus (AM5, p. 45)
  • Major Potent Magic (HoH: MC, p. 6)
  • Minor Magical Focus (AM5, p. 46)
  • Minor Potent Magic (HoH: MC, p. 6)
  • Creative Block (AM5, p. 52)
  • Deficient Form (AM5, p. 53)
  • Deficient Technique (AM5, p. 53)
  • Short-Ranged Magic (AM5, p. 59; only for spells with a Range greater than Touch)
  • Weak Scholar (AM5, p. 61)

Other appropriate Virtues and Flaws will be added to this list as they're found.

Story Flaws

A Magus or Companion may take up to two Story Flaws (although it is strongly recommended that they only take one), which will be approved on a case-by-case basis; if two Story Flaws are chosen for a character, no more than one may be Major. Selecting two Story Flaws does not increase the character's chances of being central to a story, as the Storyguide bases that on the number of active major characters and not the number of Story/Personality Flaws.

Spell Mastery Options

It makes no sense to the Storyguide that you should be able to take Multiple Casting once, take like four other various Mastery options for the same spell, and be able to cast six copies of the spell. So, going through the Spell Mastery options listed on the Atlas .pdf download, the following options may all be taken multiple times with the following benefits:

  • Apotropaic Mastery allows the magus to add his (Apotropaic Mastery) x Hierarchy score to the level of effect of the mastered spell.
  • Imperturbable Casting allows the magus to add his Imperturbable Casting score to all Concentration rolls related to the spell.
  • Lab Mastery allows the maga to add her levels of Lab Mastery to her Lab Total when designing effects that are similar.
  • Multiple Casting allows the maga to cast one additional copy of a spell per Multi-Cast slot.
  • Obfuscated Casting allows the magus to add his levels of this ability to the Ease Factor.
  • Penetration adds the number of Penetration abilities to her Penetration Ability for determining her Penetration Bonus.
  • Precise Casting, Quick Casting, and Quiet Casting add their benefits for each time the particular ability is taken, not per overall levels of Mastery.
  • Rebuttal adds three times the caster's levels with Rebuttal to the effective level of the Vim spell when determining if it can change or control the foreign magic.
  • Unraveling allows the magus to add three times his Unraveling to the effective level of the Perdo Vim spell when determining if it can destroy the targeted spell

Tremere Certamen Focus

The free House Virtue for magi of House Tremere is not a Minor Magical Focus, as it does not fit the definition given in the Virtue description. Instead, Tremere magi have the Free House Virtue Tremere Certamen Focus. This has the same benefits as Minor Magical Focus, but allows Tremere to take a Magical Focus as well. This is basically the same as outlined in ''De Domo Tremeris'' (p. 5)

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