I've been digging through my own materials all day, and I've come to the conclusion that I don't have the answer to a question one of my new players asked me: If a sorcerer were to steal a wizard's spellbook, and the book contained spells not normally attributed to the sorcerer's spell list, can they still use the spell? For example, the book in question contains the Identify spell, which isn't available to sorcerer's typically. Would a sorcerer be able to work the spell from the spellbook they stole?

Sorry if this is a silly question...I just can't read any more in-book text today and it's gonna bug me until I know the real answer lol

Unfortunately sorcerers cannot use spells from spell books. Unless, of course, as a DM you allow it. 

Here’s another thread about it

Quote from ThriKreenWarrior >>

Unfortunately sorcerers cannot use spells from spell books. Unless, of course, as a DM you allow it. 

Here’s another thread about it

I agree with ThriKeenWarior - Sorceres as a class do not study/learn magic they know it by heart (that is the flavor of the class)

The only way the wizard spellbook would be useful is if the sorcerer has the Ritual Caster feat (to copy the ritual spells) or as is mentioned in the thread you are trying to introduce a new homebrew sorcerer spell or a sorcerer spell not included in the books you allow for the campaign.

Keep in mind that even a Wizard cannot simply cast spells from another Wizard's spellbook... the in-story explanation given is that Wizards essentially write in their own sort of personal "code", and in order to gain access to the spells from another wizard's spellbook a Wizard must take the time to interpret the code and copy the spell into their own spellbook.

What you're asking about seems more appropriate to Spell Scrolls, which are intended to be easily cast by others, but again, they're limited by class restrictions. If a Sorcerer finds a Spell Scroll for a spell that's not on the Sorcerer spell list, it's basically just a fancy piece of paper for them.

Excellent. Thanks for the prompt responses! :)

If an adventure or campaign has spellbooks as loot items appropriate to find, you might consider giving the party scrolls instead. Or you could come up with some sort of houserule: a party can use another wizard's spellbook found as loot as a bundle of scrolls.

Or have NPCs willing to shell out for the Spellbook in exchange for “X.”

I've not seen spellbooks really listed as treasure (with the notable exception of a very ornate one that was just worth money on its craftsmanship alone). Clever DMs will recognize that "X level caster, Intelligence is its spellcasting ability" means the monster is a Wizard and ought to have a spellbook containing at least what's in its stat block, but I'm not sure the books actually tell them to do that.

Quote from ChoirOfFire >>

I've not seen spellbooks really listed as treasure (with the notable exception of a very ornate one that was just worth money on its craftsmanship alone). Clever DMs will recognize that "X level caster, Intelligence is its spellcasting ability" means the monster is a Wizard and ought to have a spellbook containing at least what's in its stat block, but I'm not sure the books actually tell them to do that.

 I know in Hoard of the Dragon Queen there's at least one spell book in a treasure hoard... the Adventure says for the DM to decide what they want found in the books. I believe it also says that NPC wizards should come with a spellbook that includes all the spells in their statblock, since there are several wizard enemies encountered throughout the adventure.

Although it does lead to kind of a funny situation where, somehow, only PC Wizards ever have more spells in their spellbook than they can prepare in a day. It kind of reminds me of the Pokemon games, where the only person in the entire world that has a full, balanced team is the player and like... the final boss. Everyone else has some kind of weird gimmick team.

Quote from TransmorpherDDS>>

Although it does lead to kind of a funny situation where, somehow, only PC Wizards ever have more spells in their spellbook than they can prepare in a day. It kind of reminds me of the Pokemon games, where the only person in the entire world that has a full, balanced team is the player and like... the final boss. Everyone else has some kind of weird gimmick team.

Wizards don't need to have their spellbook to be able to cast spells, they only need it to change the spells they have prepared. You're very unlikely to find a wizard out and about with their entire library with them. If they had a spellbook with them at all it'd only have the spells in it they might find useful to swap between, plus some ritual spells. Unless, like the PCs, they're murderhobos who just roam endlessly without a permanent home, or place in society, etc. Then yeah, they'd need their whole travelling library with them too.

Quote from Ravnodaus >>

Quote from TransmorpherDDS>>

Wizards don't need to have their spellbook to be able to cast spells, they only need it to change the spells they have prepared. You're very unlikely to find a wizard out and about with their entire library with them. If they had a spellbook with them at all it'd only have the spells in it they might find useful to swap between, plus some ritual spells. Unless, like the PCs, they're murderhobos who just roam endlessly without a permanent home, or place in society, etc. Then yeah, they'd need their whole travelling library with them too.

 In most of the scenarios in published adventures where this occurs, you raid the spellbook from the wizard's lair. It's simply easier to say "the spellbook has all the spells the wizard has prepared" than to devote a quarter of a page just to listing spells that not everyone can use (not to mention the reams of spells not worth spending the time and gold copying).

Back to topic, the whole basis of the Wizard is their Spellbook class feature. If you give it to everyone then it wipes out the main benefit of playing a Wizard; obviously this only matters if you have a Wizard at your table, but from a rules perspective it is clearly not okay.

Some modules have outlined sell prices for spellbooks, so a party can certainly benefit from selling a spellbook as with any other treasure.

Note, however, that the Ritual Caster feat and the similar Tomelock invocation would allow a player to copy ritual spells from the book regardless of class.

So just to put it into the proper context: the Spellbook that prompted the post was actually listed as treasure in the Dragon of Icespire Peak adventure in the Essentials kit. All the spells, save 1, are available to sorcerers at early levels, but the one that isn't, of course, was the one the player wanted to use, after discovering and taking the "treasure". She was a bit miffed that she wasn't able to use it, so I wanted to make sure I called it right before we started our next session.

I usually put together a reasonable little spellbook for a appropriate NPCs like this example: (https://www.dndbeyond.com/magic-items/1495257-sample-npcs-spellbook). If I do use a WotC statblock, I use those spells, but then I always make sure they have the minimum 6×1st-level spells for a 1st level Wiz like the apprentice wizard, whereas the 9th level mage would have the normal 8×1st-level, 4×2nd, 3rd, and 4th-level spells, and 2 5th-level. If it makes sense, like for that mage, I would give them 2 extra 1st-level spells, and an extra 2nd, and 3rd-level spell that they would reasonably have picked up and scribed. After the statblock list, I fill in some spells I specifically think the player(s) might actually be interested in, a couple spells that I know they'll not care about until that one situation pops up and they wish they had prepared it), some spells determined random, and the rest I fill in with spells they already know because it's realistic and cuts down on my work.

But I usually conceive of them as if they were PCs. And then retune them into a statblock.

Quote from Erriku >>

Quote from ChoirOfFire >>

I've not seen spellbooks really listed as treasure (with the notable exception of a very ornate one that was just worth money on its craftsmanship alone). Clever DMs will recognize that "X level caster, Intelligence is its spellcasting ability" means the monster is a Wizard and ought to have a spellbook containing at least what's in its stat block, but I'm not sure the books actually tell them to do that.

Hello ChoirOfFire,

Baldur's Gate: Descent into Avernus gives three spellbooks as treasure pretty much out of the gate, which belonged to slain wizards. My party lacked a wizard, so we just stored them and eventually forgot about them when we ran it.

 You've just reminded me that we're still carrying the one with a menacing lock on it, and we've yet to open it. I think it was the Fireball cultist's book, so that's a little spooky, but we have a lot more hit points now...

Wizards spellbooks are great treasure.  They can be used as following:

1. By another wizard to learn those spells.
2. By any Warlock with the Book of Ancient Secrets Invocation, to add all the ritual spells in the spell book to their Book of Ancient Secrets.
3. Sold to wizard to let THEM learn those spells.  I typically have players pay 1/2 the price to write it into a spellbook, which is Level of spell x 50.  So buying a spell book would be fore total levels x 25 (1/2 the price to write).   When you sell something wholesale to a shop, I give you half it's value, or total spell levels x 12.5 gp

Not all treasure can be used by anyone.   Platemail is useless to wizards, spell books are useless to most players.  But you can ALWAYS sell it