Spellbook of Knowledge is a Normal Spell Card.
Spell Cards are usually activated from the hand on your turn unless their type gives another timing window.
On the current TCG and OCG Forbidden & Limited lists tracked here, Spellbook of Knowledge is Unlimited.
YGOPRODeck lists Spellbook of Knowledge for these formats: Duel Links, Common Charity, TCG, OCG, Master Duel.
Spellbook of Knowledge belongs to the Spellbook archetype—use that tag when searching for engine pieces and tech options.
A listed print of Spellbook of Knowledge appears in 2018 Mega-Tin Mega Pack (MP18-EN076) at Ultra Rare rarity.
Among markets shown on this page, the lowest listed snapshot for Spellbook of Knowledge is about $0.16 on TCGPlayer (prices change frequently).
