Over 550 spells of dire consequences, secrets, and unfathomable power! Here are gathered spells drawn from over thirty years of Call of Cthulhusupplements and scenarios. Packed full of advice and guidance on diverse matters including spell names,elements of spell casting, magical components, and astronomical considerations.Plus flawed spells, ley lines, folk magic, and the magic of the Dreamlands. Use thisgrimoire as a resource, a play aid, and as inspiration when designing scenarios. The Grand Grimoire of Cthulhu Mythos Magic is an essential supplement forKeepers of Arcane Lore.