Dungeon Master's Guide by David Zeb Cook

A comprehensive referee’s handbook for high-fantasy tabletop role-playing that combines practical running advice with rules material: it covers campaign and adventure design, dungeon and wilderness creation, NPCs and monsters, magic items and treasure, traps and encounters, and guidance on adjudicating rules and improvising; included are optional rules, random tables, and discussions of tone, pacing, and campaign management to help a game master create consistent, engaging play.