We find codices (the plural of codex) all over the world. Some are very rare. For example, only four codices of pre-Columbian civilizations have escaped the burnings of the conquistadores. They could not be deciphered until very recently, and they provide valuable information about a civilization that had grown to a significant size before disappearing. In China, where writing first began, the invention of paper, the processes of replication and printing developed very early on. The appearance of bound volumes dated back to the beginning of our era. Classical philosophy, science and medicine that were developed in ancient China and stored in codices are used in the present day, although many also disappeared at the systematic destruction of libraries, at the decree of the first great emperor, Qin Huang Di.
But what are the common features between all these codices? Their age, civilization, language and writing are different; but all are valuable evidence of lost knowledge of the ancients. A thread connecting the knowledge of the builders of pyramids (in Egypt or South America), the Great Wall of China, and who knows, of Atlantis. The great tradition which has been erased by modernity and yet is our root.
A codex that allows us to discover, decipher and understand something profound is a priceless treasure. Anyone who is smart enough to know to decode and read one has access to unique knowledge.
Modern Day Codices
Today modern codices include games, anagrams and riddles, like the riddles linked to from the right-hand menu. If you wish to make something secret, it's more likely that you would encrypt it using computer code, rather than creating it as a beautiful document on paper or papyrus. While it seems a shame that the art of the codex is used less, online games do provide a different sort of puzzle, where instead of decoding something on paper, you are instead faced with the challenge of building cities or creating amazing fantasy lands, often in an interactive way with other players.