/tg/ Station 13 - Modules - Types

code/modules/antagonists/wizard/equipment/spellbook_entries/_entry.dm

/datum/spellbook_entry
/datum/spellbook_entry/itemItem summons, they give you an item.
/datum/spellbook_entry/summonRitual, these cause station wide effects and are (pretty much) a blank slate to implement stuff in
/datum/spellbook_entry/challengeNon-purchasable flavor spells to populate the spell book with, for style.