For Humble Bundle’s Very Humble Holiday, Adams Media is having a flash bundle sale that will give you all the skills and knowledge you need to be a great dungeon master. Raising money for Worldreader, the bundle includes 22 books collected from the Ultimate RPG series, Teri Litorco’s Civilized Guide to Tabletop Gaming, the Düngeonmeister food and drink recipe books, and a collection of mythology books to inspire your worldbuilding.

One of the only major publishers to venture into tabletop roleplaying games, Simon & Schuster imprint Adams media began publishing books about tabletop games in 2016, with Litorco’s guide that included 100 gaming etiquette rules “every gamer must live by.” In 2018, it published the Ultimate RPG Character Backstory Guide by James D’Amato, Polygon contributor and founder of the One Shot actual play network. The book offers prompts and exercises to flesh out player character backstories, creating a more fully fleshed persona for players to embody once they sat down at the table.

The success of D’Amato’s guide launched the line of guides featured in this bundle. Other books by D’Amato in this series include the Ultimate RPG Game Masters Worldbuilding Guide, the Ultimate RPG Gameplay Guide, and The Ultimate Micro-RPG Book, which includes 40 rules-lite tabletop games.

Other books in the series include the Ultimate Random Encounters Book by Travis Wheeler (which offers hundreds of encounters to incorporate into any fantasy game of your choice) and The Everything Tabletop Games Book by Bebo. The latter promises to introduce the uninitiated into the world of tabletop, explaining different genres of games while teaching strategies for winning them. Also included in the bundle are three books by Jef Aldrich and Jon Taylor: the A Dragon Walks Into A Bar joke book, the Düngeonmeister Drink Master’s Guide cocktail recipe book, and the Düngeonmeister Cookbook, which has 75 RPG-inspired recipes geared toward game-night snacks.

The final genre of books in this bundle are less specific to tabletop gaming, but are meant to provide a wealth of inspiration for dungeonmasters to pull from. That includes mythology anthologies covering specific creatures like mermaids, fairies, unicorns, dragons, vampires, and wizards, as well as culture-specific lore from Viking, Celtic, and Greek mythology. One book, by Jenny Williamson and Genn McMenemy, focuses specifically on the role of women in mythology around the world. To round it out, the final book in this bundle is A Dictionary of Made-Up Languages by Stephen D. Rogers — which is exactly what it says on the tin, and covers Klingon, Elvish, and other conlangs.

Until Dec. 19, all of that is available for less than $20. A portion of the proceeds raised from this bundle go to Worldreader, a global nonprofit organization that has donated millions of digital books to children in more than 100 countries.