Forbidden Spellbook

Forbidden Spellbook is a deep mode trinket for mages that can be found in Deep Desert Cave chests. As a mage-focused trinket, it is part of the deeper progression available in the Deep Desert region rather than an early-game drop, making it a reward tied to exploring hazardous cave content.

Its only confirmed acquisition method is chest loot in Deep Desert Cave, so players looking for it should focus on clearing and opening chests in that area.