The Manual of the Planes (abbreviated MoP) is a manual for the Dungeons & Dragons role-playing game. This text addresses the planar cosmology of the game universe. The original book (for use with Advanced Dungeons & Dragons 1st Edition) was published in 1987 by TSR, Inc. For 2nd Edition, concern over inclusion of angels and demons led TSR to forgo the release, though they compensated years later with the Planescape campaign setting. A third edition version of the Manual of the Planes was published in 2001 by Wizards of the Coast, while a new version for 4th Edition debuted in 2008. Source: Wikipedia (en)