The 'pile' of cards containing Spells and Hexes. Cards in the Spellbook tend to be more individually potent than the other card types, examples are things like Mark of the Beast, No Creature Left Behind Act and Shockwave.

a powerful tool, but it is also costly to make, requiring an investment of soul points

a text file, web page, or other method of storage which can be made available for auditing if necessary

A book of spells.