Mount&Blade/Books

Books are purchased from the Book Vendors randomly found in taverns. No one Vendor has all the books, so you will need to visit multiple taverns if you want to collect them all. There are two different Book Vendors; visually they are the same, but they carry differing titles. The first vendor sells De Re Militari, Rhetorica ad Herennium, The Book of Healing, The Life of Alixenus the Great, Essays on Logic, Manual of Arms, and The Great Book of Surgery. The second vendor sells The Book of Healing, The Life of Alixenus the Great, Essays on Logic, A Treatise on the Value of Things, Method of Mechanical Theorems, and On the Art of Fighting with Swords.

Books come in two forms. Books that state what the bonus is will grant you that bonus for as long as the book is in your inventory; this bonus will be shown in the Party window in parentheses after your base skill level, along with any bonuses granted by your companions.

Books that list a progress percentage add a regular skill point to that skill (just as if you'd spent it manually) after you have digested the information they contain, and once you have reached 100% the bonus is permanent and you no longer need the book. Each book has a minimum Intelligence level required to read it.

Reading books
In order to learn from percentage-based books you must have them in your inventory for the entirety of the reading session. On the world map, click the Camp button and choose "Take an action", then choose "Select a book to read". Pick a book from the menu and you will begin digesting the information it contains. You can only read one book at a time. You can change between books if you wish to, and you will keep your progress towards absorbing each book.

You can check what book you are reading by clicking on Reports and then Character report or putting your cursor over the book in your inventory. You read the book when ever your party is stationary, like building siege equipment or camping out. Once the book is complete a dialog box will tell you what bonus it has granted. After this you no longer need the book in your inventory.

It's best to read the books as soon as possible. Once a Stat has reached its max, the book will not provide an additional point over the maximum allowed.

Available books
These prices are raw data extracted from  using the M&B Item Editor. In practise, merchants will normally charge more for books they sell and pay less for those they buy. Putting points in Trade will bring these amounts closer to the item's true value.

Most or all of these books are named after actual historical works. Follow the linked names for information on their real-world equivalents.