Are settings well served by a big hardcover book?
Is that the best way of presenting the information?
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Flipping through a book in the middle of a game session is slow for rules, which are typically under logical headings and often have their own dedicated paragraph or bullet point. But it's so much worse when looking through a page for world information, rumors, the head of a city, etc. Important lore can be buried in a page.
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For example, let's go with
Lord Neverember from the Forgotten Realms. He's an important figure to both Neverwinter and Waterdeep. So a book on the Realms should mention him in both places, since details on that character might be needed for games that take place around either city. But printing that information twice comes at the cost of other information, so you prioritize and put it in one location, requiring people looking at the other entry to flip pages. More of the book needs to be consumed for usability.
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I'd argue digital tools (a wiki,
Epic Words, or something like Lone Wolf's
Realm Works) is likely a far superior way of conveying that information than a book. An app would also be interesting, functioning like an offline wiki or digital encyclopedia. But that's a very specialized product...