This 128-page book begins with a table of contents with a list of tables found in the book, followed by a brief introduction on page 4. Chapter 1: Building a Stronghold (pages 4–14) details a step-by-step process by with DMs and players can design a stronghold. Notes provided include how to stock the structure with gear and fill it with people, and figuring how much it costs. Chapter 2: Stronghold Components (pages 14–86) describes where and how to place items such as walls and doors, and various locations that can be placed within a stronghold. Also described are suggestions on how to place magic items, spells, traps, and siege weapons in a stronghold. Chapter 3: Strongholds in Your Campaign (pages 87–104) includes tips for building a campaign with a stronghold as the setting, as well as how to use the book in adventures that have already been established. This chapter also details how a stronghold can be attacked or defended during combat. Chapter 4: Example Strongholds (pages 104-128) provides room-by-room descriptions and maps for five detailed structures that can be used in a campaign. These include a simple keep, an undersea castle made of coral, a dwarven redoubt, a floating tower, and a citadel of the planes.
A reviewed from RPGnet said that "All in all, the Stronghold Builder’s Guide is a useful, solid product. It is well designed, clean and well written, but lacks a certain amount of flair that would have made it truly outstanding, the authors not having quite gone the extra mile."