The Original Guidebook, no longer maintained, started as simple ASCII, but has been expanded to take advantage of the more advanced features that HTML offers. However it was decided it would ban information gained via code diving. The Improved Guidebook on the other hand, besides improved interface, structure and navigation, has been expanded to include all available information, code diving not excluded. The reason for existence of the IGB is to have a SINGLE, unrestricted and complete ADOM reference. A lot of the information also comes from Sorear's Wiki and ADOM Wiki. Some statistics are from Houeland's ADOM Information.
The HTML compilation is available for download and offline reference. The most recent version of these documents will always be found zipped on the main website, igb.epizy.com. Please report any error or inaccuracy you find to pmencik at seznam dot cz; type "IGB" in the subject line. Suggestions and comments are also welcome.
The Guidebook is basically divided in three parts. The first part, which includes the "0" chapters, gives explanations on any game concept and mechanic, such as the races and classes, dungeon features, herbs, and other information that builds on information contained in the manual. The second part (chapters 1-5) consists of descriptions of various locations in the game, along with strategic guidance and details on the quests having to deal with them. The last part is the appendices, which contain complete tables of the many items in the game along with their functions, as well as a table listing all the creatures in the game along with their abilities and the effects of their corpses.
The historical work on the Guidebook was done by the Usenet newsgroup rec.games.roguelike.adom (Google Groups), but as it is mostly plagued with spam, most players frequent official forums at Thomas Biskup's ADOM site.