Book Size & Memorization?

How many pages does a typical summa, tractatus, lab text, or even casting tablet have?

I've got a player who's gained a rank in Art of Memory, and are wondering how difficult it would be to memorize a lab text or even a casting tablet with this skill. On the one hand, page count is one way to look at it. On the other, it might be ideal to set the EF for 15+magnitude for a lab text or casting tablet. It notes the idea of using Civil & Canon Law instead of Art of Memory to memorize court proceedings, so would Magic Theory be applicable for memorizing such an item? What about Ability X for a summa/tractatus of the same Ability?


I wouldn't allow memorizing and using a casting tablet, just because, it's a bit unbalancing. I would only allow memorizing a deciphered lab text (being able to understand what you read being important to memory).
EF of 15+magnitude seems pretty high as a baseline. A 5th level spell requires a 16, of Int+Art of Memory. Say you have an Int of 5 (and the Art of Memory 1, as stated), you can only memorize the text if you explode on the die. I'd probably start at EF of 9.


Why is it so unbalancing?

Art of Memory as written isn't all that useful; it is a big xp sink for something that raw Int ought to do. Real people who practice and have practiced memorization have capacities that far exceed the feeble benefits provided by AoM. Memorizing a casting tablet would still involve the usual casting penalties, plus whatever additional botch dice a GM might impose for casting from memory.

I'd have to review the rules to make a real recommendation, but I'd probably allow something.



Because it is as if you are inventing a spell in minutes rather than over the course of a season, without any of the rules for generating a lab total. And you can change it out at will, again, in minutes.

You're not inventing a spell though. You need to have an already made casting tablet to memorize. Besides the fact rare is the situation where a DM would go out of their way to destroy the casting tablet being carried. Even in the face of destruction, which Art of Memory would normally protect you from, chances are non-zero that you have more tablets than you have space in your memory palace, and it doesn't take extravagant magic to protect/repair them.

You still need the casting tablets to swap spells at will, and once you have them, you can cast at will anyway.

Casting tablet too big to carry around? That's what Muto is for.



I didn't say you were inventing the spell, I said it was as if you were inventing a spell. All of the fun, none of the guilt! If you base on on Magic Theory, it means that one could possibly memorize casting tablets (in minutes) that they wouldn't be able to invent over the course of a season.

Another point, that you raised yourself, is that if it's rare for a casting tablet to be destroyed, then the need for memorizing it is low, except to have a spell "known" to the caster that they couldn't normally invent easily through traditional means. Carry the tablet and be done with it.

By the way, I ignored this initial question:

Not sure it's relevant, except to say that the Art of Memory explicitly states that it can't be used to memorize something that is "as long as an entire text." Mythic Mimicry is the virtue necessary to memorize entire texts, such as tractatus and summae.

If it's an issue, I'd say let player make the roll, but don't let them see the result - with the understanding that failing the roll will result in unpleasantness if you attempt to actually ritually cast a spell you misremember.

"Sure, you think you remember how to cast it correctly. Go ahead." (automatic failure and 10 botch dice later) - "ooh, looks like you didn't quite recall it after all."

Personally, I'd rule that magical texts are, in and of themselves, magical - and that having a mental copy of them isn't sufficient. Such memorization would be enough to allow someone to physically make a copy to use themselves - but it's the actual act of intentionally putting effort into the creation of the text that allows someone else to use it. (Which, to be fair - is going into the "will to Power" school of magic, which isn't really Ars Magica's paradigm. But for me, it's an acceptable compromise.)

As otherwise - this allows someone with this skill to functionally learn ritual spells with no cost. Yes, you have to put XP into the Memory ability - but after that, you've pretty much got the whole of Duremar's casting tablets at your fingertips (assuming you have a character built to memorize things: Cautious Memorization, Pussient Memorization, Int +5, etc.)

That being said - if you think that's OK, then by all means implement it. Just realize that you're handing some pretty nice techniques over to the character. It also suggests that going to Duremar for a season and perusing the casting tablets is a MUCH more valuable thing to do than is suggested in the GotF. And that the Cow and Calf restrictions are much more difficult to enforce than the rules suggest. (I believe that section mentions spells that prevent magical copying/memorization of texts in the libraries. If it was possible to simply memorize a text using AoM, then this wouldn't be NEARLY as useful as it suggests.)

Actually, I don't recall the write-up for Durenmar even mentioning the availability of casting tablets. While it may be a matter of it coming out before Covenants (don't know the release schedule), I can imagine the library of Durenmar not being in the business of catering to the casting tablet market, leaving such items to be privately owned rather than available through the library.

Because Durenmar has specifically enchantments preventing memorization of books, it is therefore possible for somebody with enough skill to do it - I do not have the rules with me to check if the Ease factor is achievable or if it requires a roll above 9.
It is still a roll of 18 for 100 pages of text, which - IMO - would be enough for a tractatus, but not for any Summae.
Now the question is how many loci do you need for a whole Summae... Xp x quality pages ? So a Rote of L6Q21 is 441 pages, five locus. A L15Q15 would be 1800 pages, and a L20 Q10 2100 pages.

That feels about right. For tractatus, I would probably go with Q x 10 (YMMV, but it makes for easy math :smiley: ).

Considering that you can have a "Mental construct" as a lab (if somebody could point me where the spell/ritual to create such lab, I would gladly appreciate), I would say being able to memorize casting tablet should be doable as any written documents with the appropriate Ease factor (I would probably set it at 12 or 9+magnitude).

Regarding specifically casting tablet, I am with virgileso and Ovarwa. Considering that there is one additional skill tests to memorize, plus the inherent risk of casting from a tablet (and as SG, you can reasonably add 3-4 extra botch dices for casting from memory-tablet), I have no issue with the skill. It will remain a nice option, that character will learn to use carefully considering the risk of botches.
It is not so much different than having a pounch enchanted with a Shrinking spell allowing to carry dozen of tablets in a confortable and discrete way. Sure, it cannot be stolen, but you need to spend seasons and xp to up your skill to do so, whereas a single season is enough to make a magical pouch.

I would allow it for two reasons:

  • it is not unbalancing compared to much more abusive virtues combo which are perfectly leggit;
  • it can lead to interesting stories (how was leaked a secret ritual ? Seeking a ghost of a famous practioner of the Memory Art - or possibly be using him as a immaterial library.

If there is one restriction, it would be that I would forbid characters to use the default skill test of Int + stress die to attempt such feat.

Near the end of Covenants there is an item (a crown, iirc) that has this enchantment. The spell would essentially be the same as the effect in that item.

Am away from my (SG's) books at the moment, but I do remember that Transforming Mythic Europe has the details on pages in summae and tractarti. It's in the section about the magical technology and the like.

I remember having to look it up because I was personally considering developing an automata that can read and write a language specifically designed for, in the modern parlance, data compression, which would then be etched with magic into crystaline sheets that are much smaller than the books they started life as. While you'd need one of these automata to then read it back (magic senses to enable them to read the material via an int-terram spell, knowledge of the language and thus translation abilities, and the ability to scribe latin, and a creo-imag to create an illusionary page it 'writes' to.) the resulting items were much smaller and more portable than books, and more resilient on average also. Plus if you had it taught to actually write as part of the production method, you could also have a hermetic 'printer' in the modern parlance, since you'd load in the book, then tell it to scribe fresh copies.

Ezechiel357 can you cite where it states that Durenmar has enchantments that prevent memorization? I'm not finding it in Guardians of the Forest. The only mention of enchantments that I can recall and find is that the tower is enchanted to prevent the decay of the books within, as stated in both Covenants and Guardians of the Forest.

What are these abusive virtue combos? And while they may be legitimate, again, for any given saga or troupe they maybe wildly inappropriate.

It should then be possible for any character to then memorize a casting tablet. The ability Art of Memory is about storing the memory and then recalling it perfectly without any possible error. As stated in the ability description any character can do what someone with Art of memory does in a limited fashion, but he needs to roll Int+Stress die (with three additional botch dice) to succeed. The person without Art of Memory must roll for recall, so Art of Memory is about perfect recall. Attempts to add botch dice to the casting of casting tablets so stored is almost as much of an impediment as disallowing memorization of casting tablets in the first place, and if you do allow memorization of casting tablets, you should be consistent with the implementation of Art of Memory across the board.

It is very much different. Someone had to spend one or more seasons making such a device. Whereas, allowing memorization of casting tablets with Art of Memory allows one to memorize many spells that they may not even be able to invent in the course of a season. If one is going to allow this, I would use a rule that limited memorization of spells to be less than or equal to the lab total of the character in question, rather than ply him with additional botch dice. While it's true that it would be unnecessary if one were using a casting tablet, I find that at least such a minimum keeps consistency with the idea of inventing spells from texts and might prevent characters from memorizing a handful of spells through the Art of Memory.

TMRE, p27. Third paragraph in the Memory Palace of the Sage spell.

Thanks. It appears that the enchantment is such that it specifically prevents the use of spells (or at least that one spell) for memorization. It doesn't appear to inhibit natural memorization in any way, nor would it prevent someone with Mythic Mimicry from memorizing the text, IMO.

I fail to see how this isn't more of an argument against casting tablets, rather than a difficult (yet more secure) storage medium.

I fail to see how adding a couple botch dice would be inconsistent; as one can very easily argue that it's distracting to simultaneously split your attention between the memory palace and the physical world while casting. If the concern is one of people without Art of Memory fishing for exploding dice, they're already risking memorization botches. If one believes that adding two to four botch dice is too onerous a restriction in the face of permitting it to begin with, I would hope that botching on a memorization test should lay a nice trap on the use of a casting tablet; though I have NO idea what the base botch dice would be for memorization, as the only guideline is that it should be three additional if untrained in the Ability...

Going by Transforming Mythic Europe, using page count as the sole consideration, a level 4 summa can be stored in a single locus and a typical tractatus can be split between two loci. It would undoubtedly be an EF 21 or 24 feat to perform. The question is whether the Art of Memory's citation of "such as a long letter, but not as long as an entire text" is a guideline or an explicit restriction; which brings to question how a 100 page missive can't be considered a text while a half-size L2/Q10 summa is. And in neither case does it answer what size or appropriate complexity a lab text would be, if it even can be memorized.

I'm biased against casting tablets, it's true. I think they are problematic on many levels, see more below.

Because the ability specifically allows any memory that is stored in a locus to be recalled perfectly, it's stated in the ability description. So adding botch dice for recalling a casting tablet is inconsistent because it suggests that the casting tablet can't be perfectly recalled. If it can't be perfectly recalled how can it be perfectly memorized with a successful roll? And aren't you still dividing your attention to casting the spell with the casting tablet in hand and going back to the casting tablet to ensure that you are doing the spell in the proscribed method. Might reading a tablet be even more distracting during casting?

Botch dice are determined by the conditions at the time the ability is undertaken and applies to all abilities, normal situations start at 1 botch die. Using an untrained ability adds 3 more botch dice. So, normal conditions are 1 botch die if trained or 4 if untrained. Also, if untrained you have to make a roll for perfect recall.

Casting tablets were added because 4th edition allowed casting from texts, which is a great timesaver. However, in 5th edition, it requires a season of spell mastery (practice) and then a season of creating the text, which is a huge investment of time. The pricing of casting tablets, based on Covenants is 2 build points per 5 magnitude, twice that of lab texts, which suggests that they are at least twice as expensive, even though the build point cost isn't supposed to be used as a pricing guide. From a character perspective their cost to produce is prohibitive, because the return on it is relatively low. It might be a suitable covenant service project, I guess... But it would only be the writing of the tablet and not the mastery, as that is a benefit or continues to be a benefit to the magus even after the tablet is written, so it becomes possible for only spells that someone wants to master...

Perfect recall is different from perfect performance. I may know the exact angle to hit a billiard ball, but that doesn't change the fact my hands aren't going to hit that angle. It's just an idea seen proposed, so I'm not exactly married to the idea. I just fail to see how it's an obviously inconsistent interpretation to say that reading from your memory palace is more distracting than reading from a physical book in the act of casting.

True, but being able to perform a Casting Tablet from memory shouldn't be any harder than performing a casting tablet in hand and referring to the steps, should it? You're still doing two different things at once, casting a spell and reading or recalling the next step in the casting process. The proposal is arbitrarily harder because it has been memorized with Art of Memory, rather than having the tablet in hand. If you're going to penalize the player for memorizing the text, penalize up front and prevent casting tablets from being memorized.

Art of Memory is, from my reading of the rules, not really designed to allow the memorization of entire texts without magic; that's why we have the Memory Palace of the Sage spell, because it creates a book in your head in violation of the usual Art of Memory rules for a locus.

That's not to say that a character cannot memorize an entire text (a Muslim theologian should most certainly have memorized the Qur'an, for example) but Art of Memory has very poor rules for doing so, and I think that they are ultimately intended to prevent someone from keeping a book in their head without magic, in game mechanics terms. So I would personally forbid casting a tablet spell via Art of Memory. If you want to cast a spell from a scroll, carry the scroll with you, and if you want to be able to use the spell freely, learn the spell.