We've been asked many times about how book distribution work and how it affects the other loot drops from books. Therefore, we've exposed part of the choices that we made to create this system here.

Post associated with the comment of @Addict on loot distribution:


You guys should know that we entirely modelled the loot distribution of every container in the game and re-created a distribution of our own to match the "vanilla feel of looting".

First, our books should not take a 'loot roll' from normal books and are entirely additional to the normal loot pool, yet they still obey the same distribution model. We also have control over what kind of loot spawns where. So we made our modded book spawn in new areas that didnt spawn any books before to motivate exploration of other buildings (looting-driven gameplay).

For the details :
We explicitely made sure that no mod books should spawn in library shelves (Library/Bookstore/Classroom), where all the vanilla books can be found easily without any mod book to bother you.
Consequently, in the post-office, you can find any normal and modded books, but with very different loot distributions! (Much over 2 times more vanilla books - cf. image link below)
Only in typical bookshelves and other "rarer" places to find books that you can find both vanilla and modded books in similar distributions. In that case, vanilla books are more common in beginner levels, and slowly drift below the modded book distribution. (again cf. image below)
=> That means that you find more beginners crafting guides in homes, and a more diverse rarity levels for modded books, in slighlty higher quantity than medium/high rarity vanilla books.

Additionally, this loot distribution takes into account the relative number of looting container of each type and changes the initial weight and scarcity increase for higher level of item rarity.
=> That means that, for the same container, there should be more books total, with the same vanilla books as in unmodded games but extra modded items. A very similar distribution of type and rarity should be found accross many loot rolls (which we tested extensively) regardless of their vanilla or modded origin.
=> That also means that comparing different containers (especially the ones dedicated to new loot like army/police buildings) is not a fair comparison and that variability can be found in low loot rolls numbers.

In this link, you can find the figures for library (vanilla books), post office (vanilla books), other vanilla books places, modded books distribution (except specific places)
https://imgur.com/a/jBEqzqg