Authorities Summae Stats


An Authority is not a type of book by ArM5 (p.165f) or Covenants (p.84ff) book rules. It is a use scholastics make of a book. AFAICS this is best modelled in ArM5 by giving a book and its author a Reputation (ArM5 p.33) among scholastics, or at universities.
Principia Magica is a very special case, in that it does not hold its authority among scholastics, but among the Order of Hermes. It is an authority 'in the figurative sense' - and its Reputation should be among Hermetic magi.

Principia Magica has TMK no stats in ArM5, though IIRC it got some in ArM4 Mythic Perspectives. Given its historical importance for the Order of Hermes, the authority it holds among magi is not really relevant to determine its Level and Quality. You've received some suggestions for them in this thread.



Incorrect. That statement implies that ArM5 has sentient will. Which I grant is twisting a conclusion out of the way you phrased it. But I do think that you imagine that the authors had some unified sense of purpose and direction towards anything. Which they most certainly did not. ArM5 RAW was a deconstructed version of ArM4, with some new bells and whistles. Successive authors kept reconstructing and adding back all their favorite bits from ArM4. The only reason Authorities were not added back in is because the author that got to write expanded book rules in Covenants decided to add a dozen or more different new book ideas, and wound up creating complexity several times greater than ArM4 books had.
So there was no move away from complexity. Rather, the move was towards greater complexity.

WGRE. Authorities were described as books that could be read endlessly (infinite level sorta), with a base quality of -5. Remember, in ArM4, Abilities used the same simple pyramid scale as Arts. When studying abilities, you divided your study total by 5 round up, minimum 1xp. So, say, a Q11 Tractatus would give you 3xp and a score of 2 (from 0), and thus Ability scores progressed much faster back then, Q-5 would forever give you at least 1xp, equal to a Q5 book in ArM5.

Because if Authorities represent advanced learning unfit for novice students you need - with ArM's mechanics - to somehow discourage the novices from reading this book. And if the Authority as low quality they would rather read the low level-high quality primers on the subject. And once these are exhausted they would move on to the Authority because it is the only thing with a sufficiently high level to interest them.

If the Authority had both high level and high quality nobody would ever read anything else! Of course a sufficiently advanced author can sacrifice level for higher quality so the primers can be even higher quality than the Authority can. I'm not saying Authorities should have quality 0 or 3. I'm just saying if they are written by the best author possible with Com+5 and Good Teacher only lower level books with an even higher quality would ever be used. Written by equally proficient authors who dump level to raise quality. From a standpoint with focus on optimization.

And my point with this was that magi may want to have a go at Tractatus instead if they can find some with better quality than the Authority. Planning for the long run a magus may want to first finish the Authority before reading tractatus, to ensure he maxed out the potential exp from books on this subject.

Well, TMK and also from A&A p.136ff, early 13th century Authorities are not generally unfit for reading by novice students. De inventione certainly isn't.

Authorities just take a specific place in the organization of teaching at medieval universities. And there your idea of "unfit for novice students" might come from.

A good, early and relevant example of a pre-scholastic authority in medieval higher learning is the treatment of civil law in late 11th century Bologna (see ). They obliged their students to access the Corpus Iuris Civilis through their own lectures, glosses and commentaries: thus treating the Corpus as a 13th century scholastic would later treat an Authority.


Despite the complexity, neither AM4 nor AM4 conveys the right feel to the learning process or to the idea of bodies of knowledge.

In AM5 fundamental texts like the works of Aristotle, standard in the curriculum for centuries and still read today are either:

A Summa that can teach beginners but is of no use to truly advanced scholars.


A Tractatus (or perhaps a set of such) that can be read by the advanced but are of no more value than research texts written by students and indeed of less value if said students are particularly eloquent.

Neither of these is satisfying. Adding back AM4-style Authority rules just offers a third option of treating the works as ones which can be studied forever but which are much less useful to the student than a stack of said research texts. This isn't very satisfying either.

Increasing rules complexity isn't helping. I actually prefer the learning rules from the early editions of the game with abstract libraries and limits on learning from books but the possibility of truly legendary works as rewards or macguffins.


The rules don't let a normal person generate that book, but does allow us to describe that book mechanically. I didn't have to invent a new type of book. I only had to set an arbitrarily large number for its Level. In some cases, even the rules by which an author generates a book work just fine:

The Bible
Author: God
Maximum Level: 1/2 God's Score....




Aha! I did miss something. In the case of WGRE, rather deliberately.

To clarify, I'd really want something like the following:

Any Art or Ability that can have a score should usually have a limit on that score, based on the setting. Going beyond that limit really requires a breakthrough, because no one knows how to transcend the limit. I use lower-case 'breakthrough' because the AM rules for this do not exist at this time.

The limit should be the score of the person or persons who both mastered that ability and who transmitted that mastery to others, either by writing a book or establishing a school or by training people in his (secret?) techniques or by some other means.

For simplicity, it is reasonable to group similar abilities together. For example, Hermetic Arts might well share a single limit. Getting more complex, in some sagas it might be useful to set a limit for each Art and Ability or for a given Art or Ability to have different limits depending upon where you are. For example, Ig might have a higher limit than other Arts, and the limit for archery might be different among the Mongols compared to the French.

Reverting to before AM4, a library or similar location should describe the limits of what can be learned there, rather than text by text. Except for describing a specific datum, such as the name of a forgotten vizier or the workings of a spell, most individual texts are not really important.



An odd thought - a truly advanced book for masters of an Ability could function as a source equal to the current reader's score. A novice gains virtually nothing, but an expert learns more with every re-reading. The book continues to drop in relative value as the expert's knowledge increases - if you have a score of 8, 8 xp mean relatively little - but not so fast as a tractatus.

This would not work well with Arts.

An idle thought.

It is not hard to come with mechanics which can support any kind of books, but it all boils down to how much bookkeeping are you willing to manage. Here are some proposals:

Book for expert, but not for beginner: requires a minimum level in the Art to be used, otherwise, threat as a Summae.
For writing purpose: for each three level requirement to read the book, the author can write one level above his limit of half his Art.
Exemple: Liberius has 20 in a Art, he can write a L10 Summae, or a specialised Summae L12, min 6, or even L13, min 9. The author really focus on the most complexe aspect of the theory, assuming that the reader knows the basics.

Authorities (unlimited read until twice the level of the Summae): handle like a Summae, except that it is not possible for the writer to drop level to increase quality, the author must have at least a level 30 in Art or 9 in a skill to write an Authority and it takes twice longer to write an Authority. Once the reader reaches the cap level of the book, he can keep reading it, but the quality drops by 1/5 th of the reader level for Art (round up) or drops by his full skill for Abilities.
Exemple: Liberius has 20 in a Art (yep, the same one), and read an Authorities on it (L15, Q10). Until he reaches 21, he is still getting 10-4=6 xp per reading. At 21, he will only get 5 xp per reading until 26.

You can fine tune the numbers to speed up or slow down the progress in your Saga.

Finally, you can also allow the use of Breakthrough to increase the writing ability of a magus.
A minor Breakthrough (15 points) would allow him to write up to 2/3 of his Art, a second minor breakthrough would allow him to write up to 4/5 of his level. Each breakthrough symbolises works done to get a better understanding of the minutiae of the Art. Obviously, since it does not benefit the magus Art, only dedicated searchers or teachers would undertake this type of research.

I would recommand using cautious if you introduce both in your campaign :smiley:

Provided, that a troupe is ready to add further complexity to the ArM5 p.163ff rules for Experience and Advancement, and wishes to cover Authorities with it, here is my proposal.

It does not humpty-dumpty (see ... king-Glass ) the term Authority, and in a very simplistic fashion integrates an effect of scholastic methodology into ArM5.

What about adding the following new chapter to ArM5 p.163ff Advancement for the campaign of such a troupe?


That's an interesting approach.

Alternatively, and on a similar line:

An Author is an expert in subject or a specialized subject, who has defined or redefined an Ability. This is demonstrated by their authorship of an Authority, a summa which in retrospect has become the primary work of the Ability, laying out the generally accepted principles of the subject. An Author typically had an Ability of 10, and a Communication of 0, although some Authors are more or less able and others more or less clear, and a few are notably skilled or convoluted writers.

An Authority is a Summa, with a basic text typically Level 5 and Quality 6, which once exhausted as a summa can then be re-read as a tractatus* up to twice the Authority's Level. Authority texts are often illuminated, glossed, and otherwise subject to improvement.

*[Optional rule: the tractatus can be read once per listed specialty.]

This does not seem especially complex to me, and preserves familiar mechanics.

Nitpick: In 5th Edition, isn't the book called De Theoria Magica?

Anyway, an Authority's Quality depends on its author, like most books. Most of the Authorities were written by brilliant supergeniuses - Aristotle, for example, had Communication +3 and Great Teacher, and even Ptolemy had Communication +2. (Source: Mathing out from A&A.)

I think an Authority is an Authority because of the educational curriculum, and that having a skill means a certain familiarity with its authorities - but usually through study of other materials. For example, in Western Europe at this time, all Philosophiae can be seen as a commentary on Aristotle's work (except for the commentaries on the Timaeus - in fact, it could be argued that Philosophiae has two diametrically-opposed Authorities at this point!), but not everyone's read anything by him - their teachers might have simply created their own glosses on him for their students to read.

Some thoughts I have had about making this a new book type:
The authority is treated not as a summae (which limits the level that can be learned) but as a special form of tractatus. A person can only write one of these in a lifetime, and the initial quality is limited by both com+6(+3 for good teacher), but also limited to 1/2 the authors level in the ability being written on. When initially read for one season it will have this SQ, with ethe effective SQ declining by 1 each season it is read. Additionally the Authority may be commented on as if it were a summae, and if kept as reference while studying other works will qualify as if it were a correspondence.