I have a sorcerer who found a wizard's spellbook. She cast read magic and wanted to put some of her spells into the book for the wizard. Is this possible?
By RAW? No
Once a wizard understands a new spell, she can record it into her spellbook.
It says "wizard" explicitly, so by a direct RAW reading of the rule, no. A Sorcerer can't do it.
It also says a wizard can copy into her spellbook, not into someone else's book. That makes sense, as it's hard for a wizard to decipher someone elses magical writing (and your spellbook is meant to be your writing).
A Wizard can add spells to their book from a scroll, so a Sorcerer with Scribe Scroll could create a scroll the Wizard could then use to put it in their book.
Your DM Could Allow It
All that said, if your DM wanted to allow it? It's not a big deal.
I'd probably allow it if a Sorcerer in my game wanted to do it. They still have to pay the cost to write into the book (100g per page of the spell), and it's not exactly giving the Wizard something they can't get elsewhere anyway.
Sometimes, getting hung up on the little details isn't worth the effort. IMO, this is likely one of those times.
How would you go about allowing it? Here's a few ideas on how it might work if your DM wanted to do it:
- Have the Wizard do the writing, and let the Sorcerer act as the equivalent of another spellbook. You can use the existing rules on deciphering a spell (spellcraft check) for the Wizard to understand what the Sorcerer is saying, and if successful can copy the spell. (Thanks gatherer818!)
- Have the Sorcerer just write it in the Wizard's book, then have the Wizard make a spellcraft check using the rules to decipher someone else's arcane writing in order to understand it. (Thanks G0BLiN!)
- A Wizard can help another Wizard to learn a spell, in which case no check is required. You could houserule that a Sorcerer can also do that, in which case the Sorcerer could teach the Wizard, and the Wizard would do the writing into the book with no checks required. (Thanks Perkins!)