Codex Scientia is an official in-depth hint book for Arena written by Judith Weiler and Ted Peterson, and published by Bethesda Softworks. It came with the Deluxe Edition of the game, which was released in late 1994 and currently comes as a .PDF with the GOG.com version of the game.
The book is intended as a companion to the "Player's Guide", the manual that came with Arena. The sections of the book are summarized below
The introduction contains information on system requirements and an overview of Arena's three main playstyles: mages, warriors and thieves. For mages, high intelligence and dexterity are recommended. For warriors, the guidelines recommend a single-handed weapon and shield for higher armor classes and two-handed weapons for lower armor classes. For thieves, it gives a quick overview of the use of armor and magic and a few tips on thieving. The introduction also provides a summary of the various races.
This section describes the dangers of exploring the wilderness areas outside of the cities, how to move around, and tips on how to find remote dungeons.
Special Notes for Certain Monsters
This section expands on the manual's bestiary. It provides data on each monster's health points and percentage chance of hitting your character, as well as in-depth information on certain monsters.
Game Playing Reference Tables
This section contains four tables. The Table of Racial Starting Statistics breaks down each race's attributes by gender. The Character Class Level Advancement Table lists the experience points required per level for each character class, although it neglects to include the 1.5 experience multiplier beyond level 20. The Bestiary Attributes Table lists the attributes of each monster type. The Monster Hit-Point/Experience Point Table lists the damage, experience, health, and XP/HP of each monster. The section also contains a "Special Note" on Jagar Tharn.
Riddles and Their Answers
This section contains the answer to every riddle in Arena.
Artifacts and Their Attributes
This section of the Codex lists all of the magical artifacts available in Arena along with their properties and attributes. In addition, this section explains how to go about obtaining information on an artifact's location, and informs you that once an artifact's spell point level drops to zero, the item vanishes. It contains several errors, such as printing "Amulet of the Warlock" instead of "Warlock's Ring" and "Necromancer's Ring" instead of "Necromancer's Amulet", or incorrectly claiming that only one artifact can be possessed at any given time.
Magical Items and Their Attributes
This section contains a copy of the Metal Types table from the manual, followed by general descriptions and listings for "Magic Weapons", "Magic Armor", "Marks, Crystals, Bracers & Rings", and "Bracelets, Belts, Torcs & Amulets". At the end of the section is a listing of all potions broken down by potion type with descriptions of all possible potions of that given type, which can be used to identify unknown potions.
This section contains various game formulae, such as "Saving Throws" and "Chances of a Critical Hit".
The final section of the Codex lists all diseases and a "Holidays of the World of Tamriel" table.
- at the old UESP site