Another book on the artistry of Game Master. This books is an updated, revised, and expanded version of the previously published Lazy Dungeon Master by essentially the same team.
This book, as the name implies, advocates minimalist planning. It promises that you can do all the planning necessary for an adventure in as little as 15-30 minutes.
I believe that is a lie.
I do not believe that this method can reasonably be utilized in less than 30 minutes. I believe they chose that time frame because it would look good in advertising but I don't think it works.
The book advocates breaking an adventure down into its barest components and then just compiling lists of features (Characters, locations, items, monsters) that you just kind of pull from at random as your players drunkenly meander around.
Could it work? Certainly. But I think the cost is more than can be born. Arranging an adventure this way kind of sacrifices the barest hope of an even remotely coherent plot structure. I'm not saying you need to railroad your players aggressively, you should not. But the book advocates assembling a list of clues and just dropping them when the players do something. But clues that don't lead anywhere are kind of pointless, aren't they? And how can they lead anywhere if you aren't trying to steer your players to particular places?
Additionally, the book also advocates running mock boss battles to tweak your challenge. Well, that throws the 30 minute time limit out the window. Boss battle encounters can easily run a couple of hours. And if you're re-running this test several times to make sure the combat feels appropriately tense, you've burned days of free time on it. Running mock battles is a good idea in theory but I legitimately don't believe anyone with an actual job can really invest the time to do it. (Update: I have been shown to be incorrect on this point. Shea meant to have your villain run away or otherwise exit early fights so you have some test data by which to gauge the actual boss fight. Which sure sounds a lot like planning ahead if you know your villain won't bite it in the current fight, just sayin')
For campaign management it also advocates thinking about your campaign all the time (What are the villains doing RIGHT NOW) but also not doing any actual world building and just making it up as the players interact with those parts of the world. These two things are incompatible. You cannot do both. You can't picture your villain off doing evil things in another city if that city doesn't exist. Cities won't really make sense if you just make them up on the spot. And maybe your players won't notice but, well, maybe they will.
And the method of creating disparate adventure ideas and just kind of improvising them into an adventure really falls apart for a dungeon crawl. Dungeons have to have a sort of logic to them. And for a contained setting like a dungeon there isn't a really good reason not to assemble your room ideas into a sort of order. In fact, not having a structured dungeon will quickly make it non-functional. Are there guard patrols? How can they patrol if you don't have a layout? Dungeon ecology matters, dammit.
There is some useful material here. The idea of writing down ideas in a brainstorming session. It advocates making more ideas than you need and being prepared to discard them and that's good too. It also tells you to keep those ideas around for future adventures. I really like how it advocates multiple styles of combat (Including grid-and-mini combat as well as theatre of the mind) and I'll be stealing that where necessary.
Other irksome factors: The creators of the book conducted a survey of Dungeon Masters to collect data and they throw these statistics out.. seemingly at random? I'm not sure these why they are here other than to justify having conducted the survey. Additionally, while they generally do give credit to the source, whole pages are paraphrased from other sources and it gives the book the impression that it is cobbled together out of the work of other people. The creator even interviewed Critical Role's Matt Mercer in preparation for this and found that Mercer spends almost a full work day prepping adventures. Which must have shaken the book's author to his very core because most of the tabletop community rides Matt Mercer like he's a draft horse.
Finally the book advocates letting your players do awesome things but the examples given are probably a sign that you have let things go too far off the rails. "Players love it when they kill dragons in one hit!" Well, okay. But if they're running around killing a boss dragon in one hit, there's probably nothing left you can do to challenge them except cheese. You have probably given them too much and everything that happens now is moot. It also advocates doling out magic items like candy which I find amusing because one of the conceits of 5th edition is that magic items are very rare. This was probably done to help DMs contain power creep which has been a huge problem in previous editions.
And while awesome things can be cool, they are often anti-climactic and lack much drama. A closely fought battle feels much more engaging than a one-hit KO.
The art inside is pretty rockin' though and I'm a little surprised at the reasonable price tag on a book with so much good artwork.