Write

When you cast this spell, you gain proficiency with the forgery kit or calligrapher's supplies (your choice) for 1 hour. This doesn't consume the material component. 

If you are a wizard, you can use this spell to scribe a spell scroll of a wizard spell, or a wizard spell from a tome or spellbook into your spellbook, even if the spell is of a spell level you can't prepare. After one hour, make a DC 10 Intelligence saving throw. You have disadvantage on the saving throw if the spell is two level higher or more than the spell level you can normally prepare. On a failed save, the spell isn't destroyed but you fail to scribe the spell and you take 1d4 psychic damage per spell level of the spell you were attempting to transcribe into your book. You are also knocked unconscious for 1 minute. The psychic damage is a lingering injury that can only be healed at the rate of 1d4 hit points per day, or with a healing spell of 6th level or higher.

If you are a bard, you can use this spell to scribe a wizard spell with the ritual tag from a spellbook or spell scroll into a special ritual book. The spell must be of a spell level you can normally cast, and you can't scribe the spell if a copy already exists in your ritual book. Copying the spell into your ritual book involves reproducing the basic form of the spell, then deciphering the unique system of notation used by the wizard who wrote it. If you have your ritual book in hand, you can cast one of the scribed wizard spells once as a ritual. Once the spell is cast, the words of this spell in the ritual book fade. If you lose your ritual book, you can start a new one, but you can't have two of these special ritual books at the same time.

A spell only takes 1 hour per spell level to transcribe using this spell (instead of the usual two hours), and costs half as much (ink and substances worth 25 gp for each level of the spell). During this time, you can't benefit from a period of rest and you have disadvantage on your Wisdom (Perception) checks. Whether or not the spell is successfully transcribed, the material component of the write spell is consumed.

Based on the D&D 2nd edition spell of the same name