House Rules

Rules and any ruling in play
My rulings stand, unless a concurrence of the troupe finds the rule objectionable. Any ruling or rule of mine can be reversed by everyone at the table indicating that they don’t like it and providing a demonstration of how it affects their player character(s) directly. It isn’t enough to have a strong opinion and evidence of potential examples, you have to have everyone else and you have to demonstrate harm it does to your character(s).
When rounding, unless it is explicitly stated to round up, round to the nearest number. In the case of results resulting in a .5, round it to the nearest even number. Do not round fractions before a calculation is complete, say in a faierie aura that’s an odd number, say 3, which would normally be 1.5 or 2(by RAW). Keep the fraction or decimal for the full calculation, so a casting score in a faerie aura with an odd magnitude would be X.5.
Circles and Rings
Circles and rings are broken when crossed, or something crosses the circle, as is common in fantasy literature. If you ward something away from you and you’re within the circle, make sure that you do not cross the boundary as the ward will end.
Opening the Arts
Opening the Arts will be different in this Saga and will be done based on teaching in the Arts as they are taught individually. This becomes important when students specialize their learning early on. Whenever the first Art is opened, the students must pick a Hermetic Flaw of their choice, minor or major. That flaw will grant a bonus to later learning a Hermetic Virtue from a teacher.
Deficient Arts
Because it is possible to specialize and ignore certain Arts, whether or not an Art becomes deficient is up to the player/character. Upon reaching a score of 10 for the first time in any Art, it is possible that one of the other Arts will become deficient.
Minimum Teaching, Com and Good Teacher for Staff
The combination of these must be at least 7 for teachers. Remember, Good Teacher in face to face settings grants a bonus of 5, not 3, that’s for written works. You can elect to have higher totals, and this will improve the Source Quality for the classes you teach.
Teaching Virtues and Inherited Virtues
Apprentices introduces methods for teaching Virtues, rather it extends the rules already present in Mystery Initiations. In Apprentices, the teacher needs to get to a certain SQ, based on existing virtues, and whether or not a flaw is gained in the process. In this saga, the process is similar, in needing a target SQ, but that target SQ is gained from the year’s instruction. Subtract SQ for initiating a virtue from any experience gained in classes. Only XP from classes can be used in this manner, XP from extra-curricular activities cannot be used to acquire a virtue.
Starting Inherited Virtues
Players should allocate no more than 4 virtue points to Inherited virtues for their student characters.
Supernatural Abilities
The school does not teach these. Experience granted from the school’s curriculum cannot be diverted to these. However, extra-curricular experience points may be used for these, subject to some limitations to be determined
Tremere Aegides of the Hearth
Any Aegis of the Hearth cast by any Tremere blocks the social penalties of the Gift. This secret has not yet been shared with any of the other Houses.
Tremere Certamen Focus
The certamen abilities of House Tremere are unquestionably good. However, it fails as a minor magical focus as it cannot be used for any lab activity and only exists to improve House Tremere’s capability with certamen. It has been suggested on the Atlas-Forums that this makes the Tremere weak, but my experience is that it really doesn’t make them weaker, since not everyone has a focus. As a result Tremere may take an actual Minor Magical Focus and the house Virtue is now called Tremere Certamen Focus.
Wards and Aegides
My interpretation is that these must penetrate. Having the penetrate creates a more cooperative environment for covenants, because for high level Wards and Aegides the magi must cooperate through Wizard’s Communion.
Spell Mastery, Botch Dice and Rituals
The number of botch dice eliminated from a potential botch is equal to the score. Spell Mastery does not eliminate the risk of a botch with a score of 1 if there is more than one botch die. Rituals are always cast with a stress die and are considered to be stressful and cannot be relaxed due to the time and effort and vis involved. An 8th magnitude ritual has at least 9 botch dice before reductions due to virtues, golden cord and spell mastery.
Fast casting
The main rule book says that this is a response to an attack or other surprising event (page 83). You cannot fast cast an offensive spell in an effort to negate the attack or surprising event. Both events will occur at the same time. You can fast cast spells until you fail to succeed in meeting a given initiative point, the spell still goes off, but it goes off after all other actions are resolved. The RAW also states, on page 174, that it takes approximately one round to cast a spell, unless it is fast cast. I’m going to change that to make fast casting a viable choice for combat spells. If you expect to fast cast spells during a round, you must fast cast all of your spells. So, if you act first, and cast a Pilum of Fire, you must fast cast it if you want the ability to respond to other events with fast cast defenses.
Multiple casting
Multiple casting is a really useful spell mastery ability, but by RAW it is too powerful, especially when compared to Precise casting and Quick casting which must be taken multiple times and add bonuses of the number of times taken. Being able to fling 6 Pila of Fire with one spell casting and only a score of 5 in the mastery ability with a number of other mastery abilities chosen seems overpowered. You must now take multiple casting multiple times, and the number of times taken indicates the number of copies.
Other spell Mastery abilities
Other spell mastery abilities remain unchanged, Penetration is still a function of the ability score, as are other abilities which rely upon the ability score.
Talismans and bonuses
The bonus for the talisman was changed in errata to an adjustment to casting score, not casting total, and as such is subject to being divided. First and Second printings of the rules had the talisman bonus as a bonus to casting total which is not divided, I’m adopting this for talismans, with a slight change. Non fatiguing spontaneous spells will divide the casting bonus in half, spontaneous spells will not divide the bonus from the talisman at all.
Latin score
In addition to a minimum combination for teaching listed above, the minimum score for Latin is 5. You can decide to skip this during development and instead be taught during one of your free seasons upon joining the school. Latin 5 is necessary to write a book. Latin 4 (Hermetic) isn't sufficient to write a book even on the Hermetic Arts.

Latin score
In addition to a minimum combination for teaching listed above, the minimum score for Latin is 5. You can decide to skip this during development and instead be taught during one of your free seasons upon joining the school. Latin 5 is necessary to write a book. Latin 4 (Hermetic) isn't sufficient to write a book even on the Hermetic Arts.

Tractatus change a bit, too. Tractatus are primarily useful to those who have an underlying bit of knowledge about what they are reading. There are two similarly but slightly different rules for Arts and Abilities.
Tractatus, with respect to Arts only, can be used by anyone, but require a basic understanding in the Art and Magic Theory to be useful. In order to receive the full quality bonus of a tractatus, the magus reading it must have a combination of Magic Theory + Art of 10 or greater. For every point less than that they subtract 1 from the SQ. Tractatus read this way can be read again at a later time to recoup the remaining experience points. Any partially read tractatus should be noted on the character sheet.
Examplia Gratia: Steve has a score of 1 in the Art of Herbam, but he wants to learn more about it. His Magic Theory score is 5. He retrieves a Herbam tractatus from his covenant’s library with a quality of 10. He reads it and gets 6 xp in Herbam (MT 5 + Herbam 1=4; 10-4=6)
Tractatus for Abilities are treated similarly, but focus only on the ability score. An ability score of 3 is necessary to read a tractatus without a quality penalty, the quality penalty is 3 – present ability score. A Q10 ability tractatus read by someone with no ability score yields 7 xp, with a score of 2 results in 9 xp. Like Arts tractatus one can revisit the tractatus to recoup the missing XP, and these partially read tractatus should be marked on the character sheet, if the character has a desire to chase the few xp available.

Summae continue to be described by two factors, level and quality. Quality is still calculated as it was before, but the meaning of the quality score changes in this saga. Summae were considered textbooks, and as textbooks they are densely packed with information. One can learn from a textbook, but one learns best from a textbook when taught by a teacher. This is the purpose of the summa, to be a primary resource for teachers to prepare lessons on a subject.
The source quality for a summa depends upon how it is used. If it is used by a teacher in a classroom environment, the summa adds to his source quality as a full addition of the quality bonus. If used individually, without the benefit of a teacher, the quality bonus is divided by 5 and always rounded per the house rule, but always provides at least 1 point of quality.
Examplia Gratia: Maga Sue teaches magus Steve from a summa, the SQ of the summa is 10. Sue’s standard source quality from teaching in a single setting is 12. Her total SQ when teaching from the summa becomes 22. Were Steve to learn directly from the summa, without the benefit of a teacher, his effective SQ would be 2.

Summae also provide quality bonuses when studying from vis. They can be useful up to twice the level of the summa, and add the quality bonus that one would get if reading from the summa themselves. So a L10Q10 summa will add a +2 bonus when studying from vis up to an Art score of 20.

Faeries do not lie. They can omit, and they can use phrasing to make people draw false conclusions, but they do not lie.

The Latin Year

Apprentices are taught Latin 5 (75 xp), Artes Liberales 1 (5 xp), Philosophiae 1 (5xp) and Concentration 1 (5xp) for a total of 90 xp. The professor has a SQ of 33 when teaching, and he's teaching you all day, for 9 months. It's kind of brutal, but he drills this stuff into you. That leaves 3 xp per season which can be spent on any of the following abilities, including the ones listed above. For those with Apt Student, you have to divide the XP, so that no more than one ability receives 3 xp from Apt Student, so there will be a minimum of two abilities that benefit from Apt Student.
Church Lore
Classical Greek
Folk Ken
Infernal Lore
Order of Hermes Lore

I've stated this elsewhere, restating it here.

If you have any Arts with a score of 0 when your first Art gets to a score of 10, it will become a Deficient Art. It is highly advisable to address this during the First Year of school.

We can play it that the characters, including the professors don't actually know this, and deal with the implications of the school turning out an apprentice with a Deficient Art.

Students get 5 xp per school term (not the extracurricular season) for the purpose of acquiring Cantrips. These are low level spells of 5th level or lower. With the exception of the very first term of magic instruction these experience points are available immediately to be spent on any spell of 5th level or lower, and a teacher doesn't have to know it. For the first term, these do not become available until the end of the term. Over the course of 12 terms, you'll have acquired 60 levels of spells of 5th level or less and cannot be self-designed spells, they should come from the books, but some spells from Wizard's Grimoire might be appropriate.

On cases where the roll explodes, and the result adds enough to the total so that (casting score + roll)/5 is sufficient to cast the spell without fatigue, then no fatigue is lost. In addition all spell parameters must be specified at casting, base effect, range, duration, target, penetration, size and/or complexity modifiers.

This is to provide a small benefit to spontaneous magic in situations where the outcome is nearly certain, and one is just checking for a botch.

In Ars Magica it is trivially easy to create a min-maxed character, I think everyone here has done it in one shape. There is a fine line between creating a specialist and creating a min-maxed monstrosity. I can't tell you exactly where that dividing line is, but when I see it crossed I know. I don't want to have a lot and hard and fast rules and say no to a lot of things, but I do want you to have powerful in character motivations for certain choices and be able to defend those choices if asked by anyone in the troupe.

Players should create individual character threads for all of their characters, at first we're starting with instructors as they will take the most time to make. I'd like to see a snapshot at gauntlet and every 10 years or so post gauntlet. If you have MetaCreator you can send me the files.

This is an opportunity of creating characters that are otherwise sub-optimal. I once created a character with Unstructured Caster and Rigid Magic making formulaic magic impossible. I might even bring him here as my SG player character, or someone like him, just because this is the perfect environment for someone like that.

If you're going to pursue mystery cults, we'll work through those as they come up in your character development threads. Mystery Cults will unlock things, but often at the expense of experience points.

The only solid guideline is that your character needs to have the minimum combination for teaching of Com + Teacher + Virtue>=7. 40 xp per year for advancement and all spells are purchased with experience points (this removes the need of asking me whether a lab text for a spell is available).

Additional character building rules

Buying a LR
(Normal vis cost you would pay) + (1 per mag up to 10) + 2 per mag from 11 to 15) +(3 per mag from 16-20) + 1 season of XP sacrificed.

Characters get 5 build points worth of stuff per year. So for the typical 30 years post gauntlet character, they would start with 150 build points. It sounds like a lot, but it's not, not really when you consider some of the restrictions.

This is probably the crunchiest part of determining how much vis a character has, especially when used to compute the longevity ritual. [strike]During generation no more than 10% of your available build points at a given time can be in vis, and it is limited to an overall total of 100 pawns of used and possible vis for everyone during character development.[/strike] During generation no more than 10% of your available build points at any time can be spent as vis. Say your magus gauntlets at age 25, and acquires stuff for 10 years, and wants an LR at age 35. Such circumstances give him 50 build points, he can convert 5 build points to vis, for a total of 25 pawns. With 25 pawns of vis at age 35 he can buy a LR of: Ritual 7 + 101 magnitudes +42 magnitudes, or a total of LR 14. It's a pretty good LR. When he musters out, so to speak, and starts the saga he may not have used more than 75 pawns of vis during development, but when he musters out he can take the remaining build points and convert up to 5 of them to vis (see the 100 pawns note above). It is possible that some characters, depending on their age at gauntlet and or virtues might need two LRs due to not having enough vis at age 35, but that's not unusual in play, either. The first LR is usually the hardest to come by unless one's a specialist, and even then, a specialist will often redo the ritual later on.

They are generally off the table. I haven't posted this as a house rule, but basically Summae in Arts are primers for new magi in this saga and can't go past level 7. High level and high quality Summae are the debbil. I hate them as an SG and love them as a player. If you have an Art score below 7 at the start of the saga, we can talk about finding a summa, but that would be the exception. They would cost the standard build point cost, and have the standard build point limit. In many cases a tractatus might be a better fit. Summae in Abilities are multi-volume sets, and I need to tweak this a bit, but still it will make my life a lot easier if you don't try and bring the L6Q12 book on Parma Magica and the like.

These are available, but you may not bring more than 6. Of these, if these are in your favored Arts you may have already read some of these, but they will have other uses later on, such as trading them to the other professors. If all 6 are in nothing but your favored/highest Art, you can be sure that you've read some of these.

You can and should build items with the bulk of these build points. These aren't necessarily items that you've made, but items you've acquired or traded throughout your life post gauntlet. I may veto the Wand of Ball of Abysmal Flame with +30 penetration, as I want these to highlight how a magus will use magic to improve the comfort level of his surroundings make his life easier and the like.