Van Richten's Overall Question

[Sigreid]

If you're not interested in running the included adventure, how is it overall as a source book? Worth it?

[Unoriginal]

If you're not interested in running the included adventure, how is it overall as a source book? Worth it?

Really depends what one considers to be worthwhile.

The two subclasses are nice, so are the Dark Gifts, the monsters are pretty great (and gave me plenty of inspiration for my own ideas), there is advice on how to run curses that is interesting, and the Domain of Dreads presented can be used either as-is or for any land that might pop up in your campaign, which reduces the work you have to do. Most of said Domains aren't exactly my jam, but they're inspiring too. Haven't read the rest yet.

It's certainly not a must-have, and most of the advice isn't ground-breaking if you're experienced in DMing (in general or DMing horror in particular), but it's still neat.

[Keltest]

Unlike Tasha's or Xanathar's, it has a fairly specific genre that its acting as a sourcebook for. To that extent, it does its job really well. It doesnt just tell you factual information about the various domains, but also how to specifically run a horror campaign, how to draw the line between friendly scaring and making people genuinely uncomfortable, and how to create dark and oppressive atmospheres without completely crushing the life and hope out of your players. It also has a lot of fun undead monstrosities (and regular monstrosities) that i certainly plan to include in my campaign.

That being said, that focus also makes it a lot less useful for running, say, a regular Forgotten Realms campaign. Besides some exotic monsters, a lot of the stuff is only kind of useful if you want to play a haunted and traumatic survivor of tragedy or something similar. The book has a consistent tone that doesnt apply to every campaign. Its up to you to decide if your campaign can lean far enough in that direction to incorporate anything from the book.

[Sigreid]

Thanks, starting to sound encouraging.

[TrueAlphaGamer]

There's definitely a lot of stuff. Though, IMO, they don't go that much in depth into any one particular place or thing, and leave a lot to the reader/DM to figure out. I suppose that makes it a decent point to start off, but it can also be a bit confusing just going through looking for ideas with the express intent of using one of the domains (but not yet being sure which), as it never dwells on any one domain, and, like, half of them maintain the general eurocentric vibe of typical D&D, which makes them even less memorable.

I think if you are looking for more general ideas and want inspiration, it would help, especially with some of the monsters, or if you want to include some particular mechanics pertaining to horror or darker themes. Otherwise, you'd likely get better ideas about making a horror adventure (at least in terms of overall content and themes) by actually reading/viewing some horror or dark fantasy.