Greyhawk Adventures is an accessory for the Advanced Dungeons & Dragons (AD&D) World of Greyhawk campaign setting. Contents Greyhawk Adventures contains information about Greyhawk deities, clerics, major non-player characters, monsters, geography, spells of the setting's notable magic-users, magic items of the setting, rules for playing zero-level characters, and six short role-playing adventures. The supplement is intended to be compatible with both the 1st and 2nd Edition Advanced Dungeons & Dragons rule systems. The contents of Greyhawk Adventures represent a transitional state between the 1st and 2nd edition AD&D rules; the NPCs in the Hall of Heroes include monks, a 1st Edition character class not included in the 2nd Edition rules, while the "Monsters of Greyhawk" chapter uses the 2nd Edition's system of rolling two ten-sided dice (2d10) for monster morale, rather than the 1st Edition's d100-based morale system. Greyhawk Adventures elaborates on the religions, deities, and clerics of the setting, and introduces the concept of avatars: low-powered physical manifestations of the various deities, each of which receives a portion of a deity's power and is sent to the Prime Material Plane to carry out the deity's wishes. Greyhawk Adventures also continued the process of making clerics more individualized—begun in the second edition of the World of Greyhawk Fantasy Game Setting—by detailing such things as the use of special powers granted by their deities, the types of weapons they must use, and the types of spells a cleric may employ. Lisa Stevens thought that this section's appearance was "great", but noted as a drawback that it was missing key deities while including some lesser-known ones. The monsters in the "Monsters of Greyhawk" section are classified similarly to the existing Monster Manual books, but with additional information provided on its habitat terrain type, organization, active times, diet, and other game statistics. The "Hall of heroes" section contains detailed descriptions of some of the key non-player characters active in the world of Oerth, including: the City of Greyhawk's Lord Mayor; Constable of the City; Captain-General of the Watch; the heads of the Thieves and Assassins Guilds; Jaran Krimeeah, the Mage of the Vale; and two members of the Scarlet Brotherhood of evil monks. The book presents 106 new spells drawn from the spell books of notable wizards such as Bigby, Mordenkainen, Nystul, Tenser, and Rary. Each of the book's magical items comes with a background that ties it into the campaign setting. The