From the Magic Table: Chalk of Spell Storing

Chalk of Spell Storing

Chalk of Spell Storing is most commonly found in wizardly guild halls, academies, or other institutions of arcane learning. When a stick of this chalk is held by a wizard, they may cast any spell into the chalk, which completely absorbs and retains the spell without releasing any of its power. Any wizard touching a stick of this magically imbued chalk can immediately detect the power humming within it, and will feel a strong compulsion to use it to write upon a piece of slate or other flat stone surface.

Should a wizard holding chalk of spell storing with a contained spell apply it to such a surface, they will immediately find themselves writing out the entire formula for the spell it contains. Any wizard viewing this writing may attempt to transcribe the spell into their own spellbook, which unlike a scroll will not destroy the writing. Thus multiple wizards viewing the formula may all transcribe the same spell into their spell books. Transcribing wizards must still succeed at an Intelligence (Arcana) check with a DC equal to 10 + the spell’s level to successfully transcribe the spell into their book.

The surface will remain usable for 24 hours, after which time the chalk on the slate becomes scuffed and smudged, and no longer legible. Other physical effects that would mar the surface likewise ruins the ability to transcribe the spell. Unlike a spell scroll, the spell may not be incanted directly from the chalk writing.