(Thanks Jack Shear for getting me thinking in this direction.)
So my dungeons tend to be full of books. Books are worth Money but that's about it. Most books on a shelf need to be conveniently ruined or illegible or it's like why am I describing all these 2 sp paperbacks.
|Pictured: Not exactly a 2 sp paperback
First, get a random book generator. Vornheim's is good, but if you don't have Vornheim, this one plus a d8 and a d6 will probably do in a pinch.
Decide how insightful or informative the book is on the following scale, or roll 3d6 as if rolling an ability score modifier.
-3. Polemical screed.
-2. Poorly articulated garbage.
-1. Undersubstantiated but has a couple decent thoughts
0. It's got some decent ideas.
1. Solid piece of writing
2. Exceptionally smart
3. Essential text on the subject
N.B. Even fiction can contain very useful information! You might have to be a bit more creative about it though.
Whenever PCs have a few hours to kill, they can study a book in their possession. Make an Int check.
You know how in Dungeon World you can "hold" questions and spend them to be like "oh I already know about this" and get information about a subject? This is like that.
If you succeed on the Int check, roll 1d6+the book's usefulness (if usefulness is greater than 0, don't bother rolling). If the result is a modified 1 or lower, the book has nothing left to teach you, and can no longer be used. Otherwise, subtract 1 from the book's usefulness and hold one question.(Not sure whether usefulness attrition should be per-character or across the board. I'm inclined to say per-character but your call.)
You can spend the question to remember you totally know something about the book's subject whenever you want and ask the DM a question about the book. The DM should base the accuracy and quality of the answer on the book's initial usefulness, though even a polemical screed should have a hint of truth, even if that's what it's railing against. You can hold a total number of questions (across all books) equal to 4 + your int Modifier. PCs who already have all their questions attributed may drop one upon earning a new one.
The DM should also adjust the quality of their answer based whether you can refer back to the book and how much time you have to do so. Raising a question in combat will get you a much shittier answer than raising a question in a safe place where you can pull the book out and refresh your memory. That said, you can never earn new questions if you're reading in a hurry.
I like the idea of high-Int characters carrying books around, having an interest in books they find on adventures, and wanting to read them when they get the chance instead of rushing to find a collector so they can get the damn thing off their hands. Handling books this way might also lead to particularly useful books getting passed around the party. This little subsystem also plays nicely with my Camping Actions, and characters may even look forward to downtime as a chance to take another look at a book they have.
In Jack's post there's this cool thing where books all provide special bonuses, which is a fantastic thing to do for very rare or unique books, but this system lets your PCs grab a bunch of shit off a shelf and makes it usable with minimal work. You could have both systems in the same game.
Also kind of digging the idea that maybe instead of a question, a natural 6 on the 1d6 roll provides a special bonus, adventure hook, or maybe the beginnings of a spell formula for the DM to declare immediately.