In a game packed with infinite possibilities, what are GMs to do when their players choose what they have not prepared?

As every GM knows, no matter how many story hooks, maps or NPCs you painstakingly create during session prep, your best-laid plans are often foiled by your players' whims, extreme skill check successes (or critical fails) or their playful refusal to stay on task.

The Game Master's Book of Random Encounters provides an unbeatable solution. This massive tome is divided into location categories, each of which can stand alone as a small stop as part of a larger campaign. "Taverns, Inns, Shops & Guild Halls" section includes maps for 19 unique spaces, as well as multiple encounter tables designed to help GMs fill in the sights, sounds, smells and proprietors of a given location, allowing for each location in the book to be augmented and populated on the fly while still ensuring memorable moments for all players. Each map is presented at scale on grid, enabling GMs to determine exactly where all of the characters are in relation to one another and anyone (or anything) else in the space, critical information should any combat or other movement-based action occur.

Perhaps more useful than its nearly 100 maps, the book's one-shot generator features all the story hooks necessary for GMs to use these maps as part of an interconnected and contained adventure. Featuring eight unique campaign drivers that lead players through several of the book's provided maps, the random tables associated with each stage in the adventure allow for nearly three million different outcomes.

The book also includes a Random NPC Generator to help you create intriguing characters your players will love (or love to hate), as well as a Party Makeup Maker for establishing connections among your PCs so you can weave together a disparate group of adventurers with just a few dice rolls.

Locations include taverns, temples, inns, animal/creature lairs, gatehouses, courts, ships, laboratories and more, with adventure hooks that run the gamut from frantic rooftop chases to deep cellar dungeon-crawls, with a total of 97 maps, more than 150 tables and millions of possible adventures.

No matter where your players end up, they'll have someone or something to persuade or deceive, impress or destroy.

Jeff Ashworth is a writer, editor, storyteller and gamer whose credits include work for Disney, Hasbro, Nickelodeon, and World Wrestling Entertainment. When he isn't working on special projects for Newsweek or Media Lab Books, he enjoys playing and designing RPG games with his friends. In his role-playing career he has bested beholders, sweet-talked succubi and devastated dragons without breaking a sweat. In the real world, after failing a late-night Perception check, he was nearly crippled by a foot-piercing d4. He and his wife live in New York City with their dog, Zelda.

Jasmine Kalle hails from the sunny state of Queensland, Australia. She is an artist, mapmaker and RPG enthusiast, with a Master of Arts from the University of Queensland. She has a special love for all things sci-fi and fantasy. She spends her free time playing and leading D&D campaigns, drawing fantastic people and creatures, and petting any cat that may cross her path.

Michael Shea is the writer for the RPG-focused website Sly Flourish and the author of The Lazy Dungeon Master, Return of the Lazy Dungeon Master, and Fantastic Adventures: Ruins of Grendleroot. Shea has freelanced for numerous RPG companies including Wizards of the Coast, Kobold Press, Pelgrane Press and Sasquatch Games. Shea lives with his wife, Michelle, in northern Virginia.