You could cheat: ask what the character is looking for, make them roll $skill. If the request is infeasible, no matter the roll nothing is found.
If the request is feasible and the roll fails, they find nothing. If the request is feasible and the roll succeeds, they find a tome containing the information.
If a critical is rolled, some information comes to light that generate a plot hook. Either a good one or a bad one or just something weird.As I said in my comment, medieval libraries were a mess and required serious work to find a book even if one knew it was there. The monastery/library from should give you a nice visual if you were looking for inspirations. This seems to describe medieval libraries well but I cannot vouch for its authenticity. Seems to me that what the players are looking for in a library isn't the whole list of spells, just new or unusual ones they don't know. Yes, Program your own.Inspired by Aramis's answer, I created a spreadsheet which, following the writing rules in the book, and a weighted random distribution (to reflect the region), generates an arbitrary number of books according to the rules in the Covenants book post-errata.Nothing especially tedious, except managing the weighted distributions of books.(Theoretically, you should be able to make a copy of the above spreadsheet and javascript for your own use. Please comment if this is not so.)I then provided the following rules to my players:So, general rules of trading 'offscreen'First, I cannot replicate your insane books using the rules in anyway.
They're 'maaagic' books. They also have criamon DRM.You can't copy them because the rest doesn't work. I disrecommendtaking them out of a magic aura.General rule is: covenants are happy to trade 1:1 for 'better' books.Better generally being defined as 'in the same category.' (Forms,Techniques, General Abilities, Academic Abilities, Magic Abiltiies,Lab Texts sharing a form or technique. Other is handled on case bycase. Is usually plot-relevant. Tell me if you want to know what itresolves to, or suggest something appropriate.)In terms of 'trading up', Let's say that they're happy to have 3 timesthe build point cost in related tracticii or Lab Texts.
Shitty summaare shitty.In general, we'll use 'build points' as the currency for these things,cause OMGWTF.Bargain is actually a useful ability! (Magi only please, as most magiare snobs and won't talk to a common merchant.) for every 5% off, add3 to a base difficulty of 3 on Presence + Bargain. If you fail, theprice goes up by 10%)You may choose to, instead of getting a percentage off, to walk awayat full price but with all of the damaged books. I will determine thelevel of damage as a function of just how many damaged books youwalk away with.In terms of vis for books, prices are on page 95 of Covenants.Non-Mundane Summa are worth 1 pawn (non-vim) per level with a sworncow and calf oath. Without the oath (and therefore with unrestrictedcopying. Books are going to be more expensive).
Let's say 5 pawnsper level.Non-Mundane Tracticus are worth 1 pawn.Everything else is by negotiation.The actual spell on lab texts can be determined by you. Hell, I'mwilling for them to be quantum-indeterminant until they're used tolearn a spell from.A lab text is worth 1 pawn per magnitude.Glossed texts cost an extra pawn. Huge texts cost an extra pawn. Thequalities have not been generated as a function of the descriptor, soyou may get a deal there.Mundane Summa and tractcii are a cash exchange, which basically meanssomeone spends a plot token for 25 build points worth (I may tinkerwith this number later)Covenants are happy to trade vis at redcap rates + 10%;All of this is assuming that you can drop a staff who can copy booksfor a season. If you want books now, only look at 'copy prepared' andadd 20% to the total cost.On your travels, you can totally troubleshoot offscreen. Simplyprovide a narrative and I'll work up a covenant library and somepeople.For the sake of argument, right now you guys have three 'drop off atthe host covenant and let him copy' dudes.
After about a year ofprocessing (plus travel) you'll have original quality books.