I saw a video of the author, Justin Alexander, describing his method for running “dynamic dungeons” characterized by action groups of opponents moving and occupying spaces in more natural, realistic ways.
His presentation and rationale were crystal clear and immediately actionable, so of course I grabbed his book So You Want to be a Game Master when I saw it at Barnes & Noble.
Hoooo buddy, this book is good enough that it could replace most of the Dungeon Master’s Guide - and probably should.
The bulk of the book is about designing and running dungeons, from the extremely simple and linear up to and including multi-level mega dungeons. The advice is clear, cogent, and accessible, with topics and guidance gradually building on itself in a “workbook” style that encourages you to learn the GM role by doing it, providing the reader ample means to do so.
I highly recommend this book, especially if you’re a GM who frustrated, unimpressed, or underwhelmed by conventional RPG dungeon combat.