How to open the Necromancy of Thay in Baldur's Gate 3

A gnome holds an ancient tome, the Necromancy of Thay, in Baldur's Gate 3
(Image credit: Larian Studios)

The Necromancy of Thay in Baldur's Gate 3 is an ancient tome under the Blighted Village that you need a special key to unlock, and even then there's the question: should you open the Necromancy of Thay, or destroy it? There's value to both arguments as you stare down this Evil Dead knock-off, and we'll explain both outcomes in BG3 below - how you can open the book, what happens if you do, and what happens if you choose the righteous path and destroy it instead. Here's everything you need to know about the Necromancy of Thay in Baldur's Gate 3.

How to open the Necromancy of Thay in Baldur's Gate 3

Location of the Dark Amethyst in Baldur's Gate 3

(Image credit: Larian Studios)

The Necromancy of Thay in Baldur's Gate 3 needs a key called the Dark Amethyst, a cursed gemstone that can be placed in the mouth of the book to open it. While the Necromancy itself is found in the Baldur's Gate 3 cellar beneath the Blighted Village, the Dark Amethyst is actually somewhere else - though not too far away. To find it, you'll need to do the following:

  1. Head back to the surface and the center of the Blighted Village.
  2. Approach the old well in the town square and interact with it until you're given the option to climb down.
  3. You'll now be in the Whispering Depths, a horrible network of caverns filled with monsters called Phase Spiders.
  4. Sneak or battle your way through the Phase Spiders to the lowest and most Western point of the Depths, where you'll see a boss called the Phase Spider Matriarch
  5. Defeat or sneak around the Matriarch as with her lesser minions. On the West side of the enormous pit she circles around are some bones, with the Dark Amethyst sitting in them, glowing purple. 

Once you have the Dark Amethyst and the Necromancy of Thay in your inventory, you can try to open the book again by selecting the old tome and "Read (Character Name)" from the menu. However… should you?

Should you read or destroy the Necromancy of Thay?

A gnome considers the choice of whether to destroy or read the Necromancy of Thay in Baldur's Gate 3

(Image credit: Larian Studios)

At this point you'll have two choices - opening and reading the contents of the Necromancy of Thay, or finding a way to destroy it. We recommend you choose to read it, though save in advance in case things go wrong. 

The Necromancy of Thay is actually the center of a little side quest that lasts well into the third act, and while destroying it is certainly virtuous and will win the approval of many allies, there's a lot of potent powers to be earned if you can pass the challenges tied to it.

Reading the Necromancy of Thay

A gnome reads a magic book in Baldur's Gate 3

(Image credit: Larian Studios)

Opening and choosing to read the book will force the reader to make three Wisdom Saving Throws of escalating difficulty as they read page-to-page, the hardest of which needs you to beat a DC of 20 (though some classes and characters can get special help with these). Keep in mind that only one character can read the Necromancy of Thay.

Depending on how many you pass, you'll get different results - and obviously, you want to beat them all.

  • One success (of three): You gain the "Baleful Knowledge" curse (Disadvantage on Wisdom checks until Remove Curse is cast on you), and learn how to cast the Speak With Dead spell without casting a spell slot. You also get the "Forbidden Knowledge" buff, a permanent +1 to Wisdom Saving Throws and Ability Checks.
  • Two successes (of three): You gain the "Whispers of Madness" effect (Disadvantage on Wisdom checks for 50 turns), and learn how to cast the Speak With Dead spell without casting a spell slot. You also get the "Forbidden Knowledge" buff, a permanent +1 to Wisdom Saving Throws and Ability Checks.
  • Three successes (of three): You suffer no negative effects, and learn how to cast the Speak With Dead spell without casting a spell slot. You also get the "Forbidden Knowledge" buff, a permanent +1 to Wisdom Saving Throws and Ability Checks.

After this, the book slams shut and can't be opened again until you reach the third act, as you'll need The Tharchiate Codex found in Sorcerous Sundries. Read below to find out how you can get that in Act 3.

Destroying the Necromancy of Thay

Shadowheart casts Guiding Bolt to destroy the Necromancy of Thay in Baldur's Gate 3

(Image credit: Larian Studios)

If you don't want such evil around you, you can try to destroy the Necromancy of Thay - though that's easier said than done. Examining it reveals that it's immune to all damage besides Radiant attacks, and those aren't especially common.

The best approach is to get Shadowheart (or any cleric) to use Guiding Bolt on the book. You can't use Sacred Flame, the Cleric Cantrip, as Sacred Flame doesn't work on non-living, non-animate objects. Just drop the book from your inventory and have the character fire off the spell at it to completely destroy the text forever - though keep in mind this will summon some shadow enemies in the process, so make sure you're ready for combat, and ideally have a way to create light or see through invisibility.

How to find the Tharciate Codex and reopen the Necromancy of Thay

Baldur's Gate 3 companions party members

(Image credit: Larian Studios)

If you want to read on in the Necromancy of Thay, you'll have to find a special book at Sorcerous Sundries in Baldur's Gate's Lower City called the Tharchiate Codex. Find it in the vaults beneath the librarian's office by going through a portal and exploring Elminster's vault. 

You'll be cursed with a Constitution debuff after reading it at first, but if one of your companions (Like Shadowheart) has the Remove Curse spell, it'll be traded for a sizable bonus called Tharchiate Vigor, that gives the character 20 temporary HP after each long rest from that point on.

After reading the last few pages of the Necromancy of Thay with the Tharchiate Codex, you'll be granted a new bound action: "Danse Macabre", which allows you to summon 4 ghouls once per long rest, a powerful addition to your party.

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Joel Franey
Guides Writer

Joel Franey is a writer, journalist, podcaster and raconteur with a Masters from Sussex University, none of which has actually equipped him for anything in real life. As a result he chooses to spend most of his time playing video games, reading old books and ingesting chemically-risky levels of caffeine. He is a firm believer that the vast majority of games would be improved by adding a grappling hook, and if they already have one, they should probably add another just to be safe. You can find old work of his at USgamer, Gfinity, Eurogamer and more besides.