Codex pages can be found by training on the Agility course on Anachronia. The player receives 10 pages every time a lap is completed. There is an additional chance to find 1–3 pages when traversing an obstacle (including the final obstacle). Searching the lectern, just south-east of the lodestone at the Anachronia base camp, yields 25 codex pages; this can be done only once. At least tier three luck (such as the ring of fortune and above, or a charged collector's insignia) increases the chance to receive bonus pages from obstacles.
The codex pages can be assembled into either a Double Surge codex or Double Escape codex at the lectern. The untradeable versions of the codices require 500 pages each. The tradeable codices require 750 pages. When the player obtains one or more codex pages, they receive one of the following messages:
- You find x Codex page(s) after completing the obstacle.
- You find x Codex page(s) after completing the obstacle. As you have no inventory space, they've been placed at your feet.
Attempting to combine the pages when they are in the inventory makes the player say: "Can't do much with just the pages, I wonder if there is anything around the base camp that could help."
When used to create a tradeable Double Surge codex, each page can be valued at 29,594.49 coins. When used to create a tradeable Double Escape codex, they can be valued at 10,732.63 coins. It should be noted that the codices' current Grand Exchange values may differ greatly to what they sell for.