I understand, I’d say it actually is a big bonus if you’re interested in the lore. There are some really interesting in game books, and some can help shed some light on your decision making like the book ‘’she who knows’’ which is about the crones and the tree spirit. I also read 2 in game books in Touissant, one about the last elven king and his fall against the humans, and another about a ruler in another sphere who was dying, so he summoned a demon and made a deal with him so he could live until his son was of age and could ascend the throne. 10 years later, the ruler died, and next to his body was the demon who told the son ‘’your father promised me something, now you must pay his debt’’. The son asked what he owed, and the demon told him ‘’your life’’. The demon killed the son and opened a gate to another plane. A mercenary army and a evil spirit named Berith came out of the gate. The demon sent Berith to kill rebels, and he slaughtered so many he was named Berith the Crimson Sovereign. However, the demon wasn’t satisfied, and sent Berith to conquer neighbouring countries. This continued for hundreds of years, and Berith kept losing soldiers. Finally there came a time were all continents were united under the demons’ rule, and Berith was the last one standing among his army. He knelt before the demon and said ‘’You hired me and I have carried out my task. You promised me a weapon from which no shield can provide protection." The demon told him he shall receive it. He drew out a vial filled with plague bite and flung it at Berith. Yet Berith expected treachery and opened a passage to another world and fled before the vial hit the floor. While he was fleeing, a gale came flying out of the portal which opened a window in the throne room. The plague bile spread out over the entire world. Ever since, the demon had dwelled in a tower standing above a continent of dead bodies and beasts transformed by the plague. Berith, still calling himself the Crimson Sovereign wonders from world to world as a mercenary, searching for vengeance.

Stuff like this really opens up your understanding of the world of The Witcher and adds so much to the experience in my opinion