This is a really excellent adventure. Well thought out and fully formed. It does an superb job creating a complete world inside the of the mountain, and gives you a complete setting to add to if you want. Very well laid out for new dungeon masters. I really appreciated all the extra advice and context. I've bought/read about 2 dozen adventures on this site, and this is hands down the best.

Backed this on Kickstarter due to Sly's reputation, well worth every penny. I started a short campaign which was a mix of Out of the Abyss and Ruins of the Grendleroot. The characters and the history in this campaign book are perfect! I'm only two Grendleroot adventures in and already the players know Grendleroot mutations are bad, and the Black Star is coming!!!

I played D&D back in the 80s and have started to play again. I can say that this is perhaps the best adventure campaign that I have ever encountered. It does an amazing job of evoking a sense of wonder. The setting is amazing. The adventures are very well-constructed and easy to use. They are also built perfectly to fit an adventure into an evening. We completed most in the 3 hour range, which is helpful if you have limited time (unlike college days). You get in, have a good time, and have a sense of completion at the end of the evening. I wish the WOTC adventures were structured like this. Highly recommended!

I have invested in all Sly Flourish’s books. Ruins is both an excellent sourcebook, whether you use parts of it or run it as a campaign. There really is a huge amount of material here in a really flavorful setting. And from a GM’s perspective it is a very accessible and usable product, easy to read and navigate.

Right now this is on sale! For $4 this is a must-have addition to your library.

I can wholeheartedly recommend that book. I ran single adventures as drop-ins for larger campaigns as well as several ones in a row as a small story on their own and they were really fun to play and dm. Deepdelvers Enclave is such a nice hub for an underground area. I love it.

I am running this as a short campaign for a small party of friends and they are giving better feedback on their enjoyment playing in it than the big hardbook official books I have run for them in different groups.

• It is a great setting with fun adventures for players
• Each adventure is built from the framework of Lazy DM 8 steps
• Handy advice on how to customise the adventures for time and difficulty
• And it is essentially a sourcebook for a mountain of exploration with the lore and encounter tables in the book

Short Version: This was great.

I’ve been DMing a fairly long time, but I generally don’t use published adventures. I’ve really enjoyed Sly Flourish’s advice books, so I thought I’d give this a try. We just finished the last part of the main storyline and all the players told me how much they’ve enjoyed it.

We played almost weekly, for three to four hours at a shot. Playing through all the adventures lasted us nearly six months. We averaged two sessions an adventure, but your mileage may vary.

Everything is designed around a four character party. I typically had five or six. This wasn’t much of an issue. All I had to do was drop in an extra opponent here and there and things worked out nicely. Some encounters also have notes for scaling up important encounters for larger parties.

Honestly, I think I only even used about 3/4 of the content here. There are location and encounter generators that would easily add additional content if you felt your group needed more. There are also guidelines for continuing the plot into higher tiers of play if you want to continue beyond the presented storyline.

The only thing I can think of as a downside I’m almost embarrassed to bring up. A few of the VTT maps are scaled for 10’ squares instead of 5’. I didn’t catch it the first time, but I was on the lookout for it going forward. I can hardly complain about it, since I’m pretty sure the map pack was provided for free after I purchased the adventure. How can I complain about high-quality free stuff?

As someone who is kind of biased against published adventures, I can say this was a five-star experience for me.

I've never had more success running an adventure out of the book than I did with Ruins of the Grendleroot. Mike/Sly's style of presenting information is detailed enough that I don't feel like I payed for several adventure prompts; but, it's flexible enough to the point that I can leave in, omit, or edit elements that I want or add my own. I'd give it 6 stars if I could!

This is such a fantastic product. Not only are the adventures themselves well written, easy to run, have gorgeous illustrations and good maps, but the setting itself is such a treat and easy to adapt into other published settings! I've now adapted three adventures from the book into my own campaigns with great success and I hope run the whole thing as a mini-campaign later this year.

an Excellent in-depth campaign setting/bolt-on with interesting characters, interesting lore and a springboard setting for your own campaign. There is enough flexibility in the writing for you to adapt or integrate the content into your own game. Maps, character art and location art are provided for those using roll20/foundry (though you'll still need to add walls, lights etc) Maybe scope for a paid foundry module in the future guys, just saying :)

Great work

Awesome set of adventures in an evocative setting. Masterful tweaks on standard tropes to keep things fresh for long-time and new players. Excellent formating to quickly prepare the DM for each scene. Cannot recommend this highly enough.

I've run almost every adventure in this book and have found it to be one of the most amazing collections of adventures I have ever purchased. The setting is detailed, yet simple enough to start DMing in short order. The adventures are fun to run and offer unique challenges and encounters. I find that a quick read through the morning of a session is all I need to run an amazing session, highly reccomended!

As an aspiring DM, I found this adventure to hit on all three pillars of D&D (Exploration, Role Play, Combat). The book is broken down in easily consumable parts, the maps are straightforward, and the scenery is a fresh take that avoids 'traditional' Underdark entities.

I am running for two players (and they each use a side-kick) and so far they seem to really enjoy the adventures. Using gTove (https://illuminantgames.com/gtove) as my mapping tool and Discord for chat/talk has worked very well. The included maps import into gTove easily and character portraits and art of scenes are bonus additions.

I look forward to using the Appendices to enhance the adventures after the core stories are completed.

Having used other tools from this author, I would like to point out the high quality and thought that seems to go into Sly's creations. I have the hardback, pdf, map files, etc...and I am very pleased with the overall quality of this product.

Bought the PDF version. This book is amazing. I wanted to do an Underdark campaign for the longest time and I just slotted everything from this book into it. (Running it on Roll20 and looking for players if anyone is interested!)

Definitely a great purchase for any DM. Chock full of ideas and creative adventures.

Its a good read and I cartainly use this without too much effort. I recommend the art pack as the images are very evocative and will help you build the narrative.