in Covenant pag. 90 I read about this type of "book" and I am sure to have read about Correspondences in an other manual (but I do nor remenber where I read about it). But how this kind of books work?
If I am correct I can receive bonus XP in the same Season reading a Correspondences related to my actual subject of study!
So if I am studying a Summa of Ignem and in the same Season I receive my regular Correspondences from a fellow Magus in a topic correlated to Ignem, could I add the Summa's Quality AND the extra XP deriving from the Correspondences (based on Comunication of both writers)?
You get 1 xp per season for engaging in a relevant correspondence. The book with a quality of the combined communication scores is just what you get if you bind your letters together afterwards. (serf's parma).
so I have to receive at least a single letter per Season on a subject specifically inherent to my studies for that Season in order to be able to earn 1 extra XP. I imagine I have to pay a Mercere for having a similar service, considering that their task is to visit a Covenant at least 1 time every seven years...
I hope a pawn of vis for this will be a good offer!
A variation, from before offical 5th edition rules:
Correspondence, Spend 1 week per season active per correspondence to read their latest letter on the subject and write your reply
Each letter sent is rolled with a Stress Die for, with writers Int+Com+Subject Score(Art/3) +Language of corrspondence Score, total divided by 2, result above 10 gives receiver +1XP in subject, above 20 gives +2XP, above 30 gives +3XP etc.
Correspondence gathered together(from all involved) can be read as one tractatus for every 12 sets of letters, the quality of which is the total XP from all letters divided by number of parties involved
(clarification, Die result is added AFTER dividing by 2)
It adds a chance to get more xp from it while also adding the possibility of using old correspondence as books of it own, something that happened many times historically.
I imagine that a character might set up a correspondence with an old friend regaring magic theory and with a college who shares their most favored art (A character focussing on creating, controling and altering swords might correspond regularily with a character who invents spells concerning buildings and earthworks regarding the art of terram. A master of birds might write letters to a wolf magus about animal and so on).
In that way they'd get a bonus xp in any season where they used their favorate art or magic theory (pretty much every season).