As a skill tied to the Intelligence stat, Arcana represents the total body of magical knowledge that a character possesses. This includes what one knows about spells, mystical beings, otherworldly planes, magical languages and runes, and other occult secrets that only wizards and other magic-users may fully comprehend. A high Arcana skill can reflect a similarly high Intelligence stat, as it takes rigorous memorization to know all of these varied, alien and complex pieces of knowledge, much less distill them into facts that are logical to humans.