Some from my recent saga, that I like so much I think should be core:
First, the whole "magic is difficult" thing. It's a radical change, but in my opinion vastly improves the game-setting correspondence:
Difficult Magic : All spell and effect levels are doubled, so that casting the spells or investing powers will be harder. Accordingly, spells over (doubled) level 100 must be Ritual spells (rather than the core book’s 50).
High Magic Resistance : The Parma Magica Ability provides (Parma Magica Score x 10) to Magic Resistance (rather than the core rules’ Parma Magica Score x 5). The Magic Resistance (and penetration) of creatures of Might will be set by the SG (expect MR = Might x 2, and similar Penetration for major powers too).
Then, the Limits of Magic:
The Limit of the Eternal : Magic cannot destroy things that are eternal. This includes spiritual beings such as a person’s spirit (ghost), angels, demons, and titans. If such a creature’s Might Score is reduced to zero, it becomes incapacitated, unable to take any action; but it does not die, and in time its Might and power may be restored.
There is debate whether this applies to Faeries too, or whether faeries that are reduced to zero Might die but are replaced by other faeries that take their role.
The Limit of the Realms [p. 80] : Hermetic magic cannot affect anything in another Realm of Power. A few spells, such as Incantation of Summoning the Dead , are an exception to this; these spells cannot be varied or invented from scratch, only replicated from lab texts.
If a magus somehow finds himself in a Realm of Power, his spells could affect things in that Realm, but would not be able to affect anything in the mundane world or in some other Realm.
House Bjornaer [p. 91] : The Heartbeast Ability may be added to the casting total (or Lab Total) of Muto Corpus or Muto Animal spells, as long as these do not constitute change into or out of other (not An or Co) Forms. In addition, add (Heartbeast Ability x 5) to the Magic Resistance of a Bjornaer against Intellego spells. This stacks with Parma and Form.
House Criamon [p. 92] : Enigmatic Wisdom may be used instead of Philosophiae when casting Intellego spells ritually or with Ceremonial Casting. In addition, a Criamon magus can cast any Intellego formulaic spell he knows using Ceremonial Casting.
House Merinita / Faerie Magic [p. 92]: The spell parameters allowed by Faerie Magic are altered as following:
• Bargain is no longer a duration. Replace it with the following rule:
A spell can be cast as a Bargain on someone who has just concluded a bargain or agreement with the maga. The maga enjoys a +20 to Penetration, but if the spell penetrates the target’s magic resistance nothing happens unless the target breaks the bargain. If he does, the spell takes effect without the need to bypass magic resistance again, and lasts its usual duration from the moment it is activated.
A spell cannot be designed as a “Bargain spell”, instead a maga with Faerie Magic can cast a spell as a bargain.
• Until (Condition) duration is altered. Make the following changes:
The spell ends if the condition is met, or if the caster dies or goes into Twilight or any Realm of Power. The spell can also be suppressed or dispelled by other magic just like any other spell. Until (Condition) is the same level of duration as Year (+4), and casting it requires the same amount of raw vis as a Ritual spell, but the spell need not be a Ritual just because it has this duration (although it may be a Ritual spell for other reasons).
House Tremere [p. 30] : You may take the Skilled Parens virtue, instead of the Magical Focus in Certamen the core rules mandate. In addition, your character may lend equipment worth 5 Build Points from the House each year. These points can be accumulated if not used, to loan bigger items. Note that “loaning” a raw vis source for a year is the same as permanently receiving its annual supply. On the flip side, your character is expected to spend 2 seasons per decade on House-mandated tasks, such as fashioning magic items or books for the House to lend.
And some other rules:
Confidence Replenishes [p. 20] : The character’s Confidence Points return to 3 (or whatever their baseline quantity is) every day, unless he has more points, in which case he retains them. Because this way NPCs can reasonably have Confidence - which some can use to cast magic x-times per day! - and because it encourages the use of Confidence by the PCs.
Fast Caster [p.42]: In addition to increasing your Initiative, this virtue adds +3 to your (Quickness + Finesse) total for the purpose of determining how many fast-cast spells you can cast in a round.
Mercurian Magic [p. 46] : In addition to the core book’s benefits, you may also cast any Formulaic spell you know using Ceremonial Casting.
Code of Hermes: removed (use Order of Hermes Lore). This means magi must start with a score of 1 in Order of Hermes Lore.
Props Needed [p. 81, 83] : Casting a Ritual spell, or casting a spell using Ceremonial Casting, requires props such as drawing arcane symbols on the ground, using specifically-colored robes, lighting incense, placing resonant items at key points, and so on. The character is generally assumed to have the required items on his person or easily available, unless the SG rules otherwise.
True Names [p 84]: When learning (Realm) Lore, the character may gain the knowledge of one True Name per 5 XP gained in the lore.
A True Name requires words, gestures, and inscriptions (drawing out mystic symbols) to be used. This is a house rule; True Names otherwise work like in the supplements.
It is impossible to discover something’s True Name by Hermetic means, and the Order does not know how these were once discovered. Accordingly, this benefit is only applicable when learning from ancient (Realm) Lore sources. Such sources can only contain the True Names of ancient beings, from Roman or earlier times. These may include the true names of demons, angels, Faerie gods, titans, and so on, but also of more minor spirits such as a panes (spirits protecting the pantry from rot) or lares (spirits protecting the family). Also a house rule
Multicast [p. 87] : If you choose the Multiple Casting spell mastery special ability [p. 86], you may cast one more copy of the spell. Doing so lowers the penetration of both spells (the original and the copy) by 10. You may take this special ability one more time, to be able to cast the spell three times in a single action with -20 to penetration.
Because the power-increase of the core rules' Multicast is bananas.
Twilight Time Override [p. 88]: The SG can shorten the time spent in Temporary Twilight arbitrarily, to keep the character in the story and saga.
Because Twilight is cool, but can suck a character out of a saga.
Magic Item Penetration [p. 99]: The penetration of an effect you create is limited to your (Lab Total)/4.
Because magi should be fighting the dragon, not a grog with a "dragon-piercing spear"
Wards [p. 114] : Replace all ward General guidelines with the following guideline:
Level 5: Ward against creatures of this Form from one Realm (Divine, Faerie, Infernal, or Magic). A ReVi spell may instead affect any being of Might from one Realm, regardless of its Form. The spell affects any appropriate creature with (Realm) Might, if it penetrates. (Range Touch, Duration Ring, Target Circle)
Because the current scheme doesn't mesh well with the rest of the rules, and needs far too many essentially-indentical guideliens
As per p. 114 in the core rulebook, wards can be designed with other spell parameters.
Difficult Invisibility [p. 146] : The spell Veil of Invisibility is Pe(Re)Im 30 (Base 4, +1 touch, +2 Sun, +1 changing images, +1 Re requisite, +1 change along with object). The core book’s (level 20) version of the spell is called The Living Shadow , and turns the target into a black silhouette. These are the pre-doubling levels.
Because fighting invisibly isn't fun.
Similarly, the spell Invisibility of the Standing Wizard is Pe(Re)Im 20 (Base 4, +1 touch, +2 sun, +1 Re requisite), and Chamber of Invisibility is Pe(Re)Im 30 (Base 4, +1 touch, +2 sun, +2 group, +1 Re requisite).
Changing Size [p. 192]: For each +1 to Size, add +2 to Strength, +2 to Stamina, and -1 to Quickness [the core rules don’t modify Stamina]. This modifies the combat stats by -1 Init, -1 Def, +2 Dam, +2 Soak. In addition, add +1 to the wound range. Reducing size has the opposite effects (wound range minimum is 1).
Without this change, Size is a disadvantage in combat.