Sorry to be a pain. Is there anywhere else Casting Tablets are explained?
According to http://www.redcap.org/page/Casting_Tablet, they are defined in Covenants (Fifth Edition) pages 89-90 as a (normal!) book that allows a Magi opened to the Arts to cast a specific spell in a specific way, with certain limitations.
I was always under the impression that they were some sort of enchanted device that required at least 1 pawn of Vis to create. And I have half an idea that it was possible for non-Magi to attempt to use them. Am I mistaken?
Background for asking this:
Companion Redcap is questing to deliver a valuable bequest to a Verditus magus who disappeared two years ago in-game. A Verditus who can be recognised because his casting tools are overly elaborate in the form of casting tablets of the spells, that he casts using Flexible Formulaic Magic, the casting tablets collected in a large folio.
Now it sounds like my Magus, who has mastered all his spells, will be asked to create Casting Tablets.
No vis is needed to write or copy a casting tablet.
This Verditius appears to use highly saga-specific rules.
Otherwise, casting from tablets (Covenants p.90) is just executing a sequence of actions one does not understand. So ArM5 p.42 Flexible Formulaic Magic does not apply to casting from tablets.
I think the SG was saying the Verditus NPC has an extra Flaw requiring the casting tools be casting tablets - maybe a Necessary Condition.
By telling us the NPC has Flexible Formulaic Magic, I think he was saying that the NPC only uses the casting tablets as Verditus casting tools, rather than reading the tablets. Though I could be wrong.
I think it is maybe a setup for our group to get treasure in the form of extra spells to cast, as the clue to finding the NPC seems to be that a pirate leader has been seen with a magic item that is recognisably the NPCs favourite enchanted item, suggesting the NPC could be deceased. Though I think the SG means highwaymen, as the "pirates" don't seem to have a ship, and are operating quite a distance from the sea.
Non-Magi cannot use a casting tablet. Casting tablets give no benefit when inventing a spell. Tablets are written out by Magi at the same rate they copy their lab texts, but as noted, they can only write out tablets for spells they have mastered.
If you have a memory of casting tablets working differently, you may have a former edition messing around up there. Or another game entirely. The idea of "books with spells in them which take a long time to cast and are potentially dangerous" is replicated in a lot of other games. But in Ars, casting tablets are tools for Hermetic Magi and useless to the unGifted.
I remember a scenario where non magi were trying to use casting tablets getting then an automatic botch... so yes, a non gifted (or non opened to arts) person can try... but will necessarily miss and create probably a kind of strange effect...