D&D 5E My guesses for what will be in the Book of Many Things

[humble minion]

I'm honestly starting to wonder whether it might not be generic sourcebook in the vein of Xanathar's and Tashas, just with a bit of a theme of the Deck. The whole Many Things/Everything title parallel is a bit suggestive. There's lots of subclasses from Ravenloft, Fizban's and so on that haven't been compiled in a book yet, as well as subsystems like the relationship mechanic from Strixhaven, and that's the sort of thing WotC loves to reprint if they do go down that path.

Unless they stuff the book entirely with encounters, mini-adventures etc to the point it's more like yet another adventure compilation rather than a sourcebook, then I honestly have no idea how they'd fill the pagecount of a full-sized hardcover with purely Deck-related material without masses of padding. Even Fizban's was straining for content, and surely dragons are a bigger topic?

 

[Whizbang Dustyboots]

I'm honestly starting to wonder whether it might not be generic sourcebook in the vein of Xanathar's and Tashas, just with a bit of a theme of the Deck. The whole Many Things/Everything title parallel is a bit suggestive.

I have similar thoughts.

 

[LordEntrails]

Yep, I'm with @humble minion
The entire book is not going to be X pages for each card in the deck. Sure, I expect their to be a short adventure for the Donjon and Throne etc. But other than that, I expect it to be lots of new miscellaneous stuff.

More magic items, maybe exotic weapons, maybe pets, or rules for other stuff (more downtime activities, environment rules...)