Chains of Asmodeus is a newly released official sourcebook for Dungeons & Dragons on DM's Guild. With a $29.95 price tag, it’s hard for many people to justify the cost of a PDF download. This is especially true since it doesn’t tie into D&D Beyond. (The product description does say a print-on-demand copy is in the works, as well, and there may be Roll20 integration eventually, too.)
However, not giving the book a chance is missing out on some of the best D&D that Wizards of the Coast has published in years. Technically written and developed by Arcanum Worlds, Chains of Asmodeus was commissioned by WotC and published under their label on DMs Guild, making it official D&D 5e content.
5. It's For Charity
Yes, Chains of Asmodeus is just under $30. And that's a lot for a DMs Guild purchase. However, this money isn't going into Hasbro's pocketbook by way of WotC. All proceeds from the title are going directly to the Extra Life program and the Children’s Miracle Network Hospitals.
That alone is enough to justify the purchase, I think. Consider it a donation to save a kid's life, if you want to, and you get a hella cool (see what I did there?) book as a bonus.
4. Chains of Asmodeus is 286 Pages Long
For a D&D book, that's pretty looooooong. Depending on the book, 5e releases from WotC don't get into the ~300-page range like CoA does. A lot of that has to do with printing costs. Tasha's Cauldron of Everything, Planescape, Spelljammer, etc. are about 180 pages with campaigns like The Wild Beyond the Witchlight and Keys from the Golden Vault clocking between 200-250ish.
Being digital-only lets Chains of Asmodeus be as long as it needs to be. The bandwidth and distribution costs are negligible for whether it is 180 pages or 286 pages.
That's also why it's $29.95. Because that's a lot of content. A whole lot of content. And since it's both a sourcebook on the Nine Hells and an adventure that takes the characters from level 11-20, there's not much of a downside to signing this devil's contract.
3. It's A High-Level Adventure For Levels 11-20
One of the biggest complaints about fifth edition is that there is exceptionally little high-level content. Most Dungeons & Dragons 5e adventures cap out between 10 and 13, with a rare book having more than that. For instance, Candlekeep Mysteries has adventures through level 17. The 5e Planescape box set goes to 13, then skips to 17.
But these are the exception and not the rule. I can't think of a single official DnD 5e adventure that even touches level 20 at all until Chains of Asmodeus.
Note: If you know of an official one for level 20s in 5e, leave a comment and please let me know!
(Update: Thanks to the comment from Jude Mapp letting me know that Dungeon of the Mad Mage does hit 20. I didn't know that until right now!)
2. Sequel to Baldur's Gate: Descent into Avernus
While Chains of Asmodeus can be used entirely as a sourcebook and standalone adventure, the whole thing is also made to be a direct follow-up to the hardcover 5e adventure Baldur's Gate: Descent into Avernus.
Coincidentally, Avernus takes players through the first level of the Nine Hells and caps out at level 13. In Chains of Avernus, players go through the other 8 levels of hell and start at level 11. So the range is perfect as a continuation.
Asmodeus himself plays a major role in the narrative of Descent into Avernus, though he's never actually a direct threat to the players. That's not the case with Chains: there's a CR30 stat block for his Avatar in there and everything.
1. One Of The Writers Also Wrote Baldur's Gate 1 and 2
James Ohlen, co-author alongside Hugo-award winner Adrian Tchaikovsky, was the lead designer of the original Baldur's Gate games for BioWare. Since 2018, he founded the publisher Arcanum Worlds and is currently with Archetype Entertainment, a development division of Wizards of the Coast.
Basically, he's got the credentials to do this right. He was also lead designer on Neverwinter Nights and Knights of the Old Republic. If that doesn't convince you to pick up Chains of Asmodeus, I'm not sure what will.