From the designer's blog: Dyson's Delves is a 6″ x 9″ 149 page book of adventures and maps for your old school game. Five full adventures from the site begin the book, followed by 44 dungeon maps each with a lined page opposite it for the owner to stock and key the maps or just to write notes about the dungeon for his or her own game. From publisher blurb: Customize your dungeons! Adventures and maps set under the earth for old-school fantasy roleplaying games (OSR games). Dyson's Delves contains over 140 pages of maps and adventures featuring the unique mapping style of Dyson Logos. Five full adventures fill out the beginning of the book, followed by 44 additional dungeon maps each with a page for the GM to key and make notes about each dungeon. The adventures in this volume are: Dyson's Delve - an 11 level crawl that takes characters from level 1 to level 6 The Charmed Grotto - a subterranean adventure for characters levels 5 to 8 Ruins of the Gorgon - a smaller adventure for level 4 characters The Worm's Gullet - award-winning adventure for levels 4-6 Erdea Manor - massive four-level crawl for levels 3-6 Each map in the second portion of the book is presented on it’s own page opposite a lined page that you use to indicate where the dungeon in question is, what it is known as on your campaign map, as well as what is important about it in your games. This book is designed at 6x9 layout, not letter - which means it uses single-column text which entails easier reading on electronic devices.