Cypher Books

These books, always sold in identical pairs, contain numbered grids on each page which simply and easily catalog random lists of words. This allows a user to write messages which substitute letters and numbers that reference the page, row, and column of a particular word found within the cypher book. A creature without access to the appropriate cypher book takes a –10 penalty on Linguistic checks made to decipher each page of a coded message. Writing a message using the cipher takes 10 times as long as writing an uncoded message, and decoding it with the cipher book takes as much time as writing the original coded message.