Should you give the Necromancy of Thay book to Astarion in Baldur's Gate 3 (BG3)?

Of all the dark secrets encountered in Baldur’s Gate 3, the Necromancy of Thay might be the most sinister. It’s one book you can certainly judge by its cover, as the book is just as twisted on the inside as it is on the outside. Upon discovering the Necromancy of Thay book, you’ll be faced with one dilemma: who do you let read this thing?

The Necromancy of Thay is a book of dark magic that once belonged to a necromancer who practiced his craft in a hidden workshop beneath the apothecary in Act 1’s Blighted Village. All of your party members have big reactions to the book, but Astarion is particularly intrigued by it. 

The pros of letting Astarion read the Necromancy of Thay

If you’re traveling with Astarion and want to improve his opinion of your character, you should let Astarion read the Necromancy of Thay. It’s not a big deal by any means, though.

While you can give the Necromancy of Thay to anyone, yourself included, letting the party member interested read the book pays off. The upside here is that you’ll win his approval and hear unique dialogue. However, it’s not a part of Astarion’s quest, and there are plenty of other ways to improve favor. If you choose someone else, your relationship with him should be fine. So, ultimately, you can forgo the extra approval and give the book to whichever party member makes the best use of its ghoulish abilities.

Taking a peek at forbidden knowledge

After you’ve grabbed the Necromancy of Thay and figured out how to open it, its owner can try to read the book’s three pages, but whoever does it will have progressively harder Wisdom checks. Most checks have a DC of 10, 15, and 20, but some classes like Sorcerers, Bards, and Clerics have DCs lowered by 5.

Upon first failing a check, they’re cursed with Whispers of Madness, giving them disadvantage to Wisdom checks for 50 turns. On the second failure, they’ll get Baleful Knowledge, which has the same effect until casting Remove Curse. 

Passing the first Wisdom check rewards the Speak with Dead ability without expending a spell slot. Passing all three grants the Forbidden Knowledge trait. In Acts 1 and 2, the trait gives a character +1 on Wisdom saves and ability checks, but in Act 3, it yields a free +2 attribute boost from the Mirror of Loss. 

In Act 3, if you steal another book, The Tharchiate Codex, from the Sorcerous Sundries vault, you can read the Necromancy again. Passing another DC 20 Wisdom rewards Danse Macabre, a spell that summons four ghouls to fight alongside you once per long rest. Ultimately, just give the Necromancy of Thay to whoever you want to become your dedicated ghoul summoner.