Codices

There was a time in the earliest Ages of Man when magic was new, and wild, and understanding it shaped it, constrained it. And thereby constrained the world. The greatest sages wrote their understanding of magic, of fire and shadow, of machines and time and the universe itself into their great works, the codices. Each codex is a powerful magical tome, an artifact unto itself, and unlocking its knowledge instantly makes you one of the most powerful people in the world. No sage is known to have written more than one, and each author was in their lifetime famous as one of the greatest practitioners of magic in all Orden. Each codex requires attunement and thus no wizard could benefit from more than three at once, but even that would be a historical first. These books contain so much power that they have a personality of their own and do not like being in close proximity (say, 500 miles) of another codex.
They aren’t items you can run around and collect, and no one knows how many there might be. References in the Libraries of Sigil suggest there could be as many as a hundred such tomes, but that list was compiled from unverified and in some cases outright unreliable sources. Attempting to copy a codex produces a book with all the words in the right order, but no magic and no effects.

Attuning to a Codex

All the codices require attunement, which requires the reader to spend a month in uninterrupted study of no less than 8 hours per day and 48 hours six days per week. Once attuned, the owner of the codex need not take the book with them. They can leave it in a secure location and still gain its benefits, but must refresh their knowledge through 8 hours of uninterrupted study once per month or else lose its benefits.