As the original volumes of the game system (Monster Manual, Players Handbook, and Dungeon Masters Guide) have altered from their first editions, so the game has changed in form and substance. This new material grew from my own campaign, articles published in Dragon Magazine, and input from many Dungeon Masters and players also. The book has a single purpose: Unearthed Arcana brings new dimensions to the AD&D game system. The compiled material which lies herein offers fresh new approaches to play without materially affecting any ongoing campaign adversely. This work does not alter former "laws of the multiverse," but it does open insights and vistas beyond those previously understood and seen. . . .
Every Dungeon Master who has created a campaign milieu out of whole cloth, so to speak, can certainly understand that the more one learns, the more one comes to understand how little he knows. So too the multiverse of this game system. The farther afield one goes in exploration and discovery, the greater the realization of how vast is the realm of unknown knowledge which awaits discovery, as it were. However, such as with our actual world, the expanses of the game multiverse will always have frontiers and unexplored territories. This fact, indeed, is what makes the AD&D game system so wonderful and appealing.