[House rules] Books (or Reversed detailing pt II)

You'll certainly learn something from a beginner's book, but not something comparable to what you'd get from reading a scholarly treatise appropriate to your level of understanding. Give me a copy of "The Complete Idiot's Guide to the Middle Ages" and I'll certainly pick up on some names and dates I'm not yet familiar with but I'm sure I won't learn anything substantial. Similarly, "Our Friend the Atom" isn't going to help a professional physicist, although it may include some interesting trivia on barium that he hadn't known before.

This comes back to my suggestion that working in a library of lower level tractatuses be treated like Practice. It's a general match to the definition in AM5 that "A character can try to deliberately find out more about a subject, by her own efforts". It's not the wisdom in the student paper that helps, it's the activity of concentrating and thinking about the subject.

For me, a source quality of 4 (the default practice level) isn't bad, since I assume most tractatuses are written by magi with average communications. If your characters never read books of quality lower than 13, then I suppose Practice is pointless. For me it's not a bad way to approximate studying without expert texts. And yes, I realize by RAW you can't practice the Arts; that's where having these lower level tractatuses gives you a bonus.

Yes. This is exactly the point. This is why in ArM character's "Study a Tractatus for a Season" rather than merely read it in a few afternoons. However, the character is still studying from the tractatus, the catalyst needed to be present.

Also, as others have said, the impact on the character of gaining, say 8 XP is strongly dependent on his existing Art (or Ability) Score, because of the pyramid advancement scheme.

Imagine this situation. There are three magi, an apprentice (Noobius, 0 Terram Art Score), a master (Meritus, 10 Terram Art Score) and an arch-magus (Arrogus, 30 Terram Art Score). Meritus writes a Quality 8 Tractatus on Terram, and Noobius and Arrogus each study a copy of Mertius' book.

Noobius reads the book and gains 8 XP, which increases his Terram Art Score from 0 to 3(2). He now understands much more about Terram, and if he tries hard he can now pretty reliably cast a Spontaneous Magnitude One Terram spell, which is something that he could just about do before reading the book, but only if he was lucky. He is significantly more skilled at Terram than he was.

On the other hand, Arrogus reads the book and he agrees with much of what Meritus has written, but Meritus is plainly wrong in his descriptions of the process of how vis is consumed during Terram rituals. Arrogus carefully studies this aspect of Meritus's book, and thinks, "Ah, I see. Meritus is such a fool. He has done all of his experiments with Terram rituals at the same location which is the intersection between a Lesser and Inverted Major Lay Line. Meritus has not realised that this is interfering with the Ethereal Vis Decay pattern that he is seeing." By showing how Meritus' errors have been made Arrogus gains a slightly more complete understanding of how Terram works. Arrogus also gains 8 XP, this increases his Terram Art Score from 30 to 30(8). Arrogus can't effectively do anything new, but after another few seasons of studying (other books) and demolishing the authors' arguments he might raise his Terram Art Score by 1 to 31, which actually doesn't really make much difference to his Terram Casting Total, anyway. Arrogus does however enjoy writing a smug letter to Meritus.

Now, this is not the only valid explanation of how Arrogus could learn something from Mertius' book. It could be that Mertius' book does contain a new snippet of information that Arrogus didn't know, or just has a slightly different way of looking at stuff that Arrogus did already know. However, this explanation just requires Meritus to know less about the Art than Arrogus, rather than Meritus somehow having a special insight.

Of course, as players we don't really need to know precisely what is happening at this level of detail, and we can't know because Terram doesn't actually exist as a body of knowledge in real life. This is why the rules just deal in the abstract; read the book get 8 XP. As Direwolf points out attempting to make this part of the book rules less abstract just results in them becoming more unrealistic (not to mention difficult to play).

I am not sure you thought this through. Magi are scholars, 15 years of apprenticeship is a Bachelor's degree. Tractatus are scholarly papers from Master's students and up.

"Population Movement around Luton during the Viking Invasions" and "Study of Inheritance in Luton during the Hundred Years' War" are 2 tractatus that could be written by modern Master's students, there's very little overlap between the 2 and even a renown medievalist might know nothing of these if he didn't specialize in British Middle Ages.

Pick a science, any science. There are too many parallel branches to explore, you cannot linearize it all as a number and then state: "Everything below that number I know."

What makes you so sure that books on the Arts are all on broad subjects instead of in-depth knowledge? In your example earlier of the book on sandstone, reading it and getting XP in TE would make the magus better at magicking granite, limestone, metal, or dirt, as well as with the aforementioned sandstone. If you're looking for a specific equivalent of a detailed research paper, that's probably a lab text on a spell to create sandstone. Otherwise you're going to have to come up with an explanation of how learning details of "Population Movement around Luton during the Viking Invasions" helps me write a paper on Persian traders in the Mongol Khanate.

It doesn't. Real life has no Ability score.

So then was there actually a reason you were trying to compare books on the Arts to graduate student research papers if you see no analogy whatsoever?

Yes, because of the limitation of Ability score, you have to accept that in Ars Mag "learning details of Population Movement around Luton during the Viking Invasions helps [you] write a [tractatus] on Persian traders in the Mongol Khanate."

Whereas I would say that your analogy just doesn't work. One of two things must be true. Either the Real World(tm) and the world of Ars Magica are so different that there's no valid analogy whatsoever between skills in the two, or there actually is a relationship and it suggests that research papers don't have much in common with the tractatus.

If you want Abilities to be linear in your saga, so be it. I am not taking that road and my reasons are clear.

That specific level of detail better fits a Tractatus on a Spell Mastery Ability rather than an Art.

RAW, they are at least somewhat linear. Art and Academe's example of a goldsmith learning progressively better(and more time-consuming) techniques as he increases in skill, for example.


As in getting similar results. To be completely linear they'd have to learn the same techniques. I believe each master had his own technique to reach such a fine result, which might be based on different preparations by journeymen. Many of those trade secrets were lost, some rediscovered (Stradivarius, anyone?).

If you mean to say learning 2 different techniques cannot improve the result, I can live with that. It can be very true for narrow Abilities such as Goldsmith but wider Abilities with multiple end products have many parallel learning tracks. This fits rather well with RAW tractatus which are definitely not linear.