Bundle of Holding has an interesting new offer which is a departure from their usual tabletop RPG gamebooks:
Designers, Dragons, and More consists of non-fiction about the history and design of games and player culture.
The prize draw in this is the 4-volume Designers & Dragons, which was a Kickstarter-funded history of D&D and spinoffs and imitator RPG games and the gaming industry throughout the decades, for which you can
download a substantial preview chapter about TSR (
Wikipedia, one of the major companies) on the publisher's website. Apparently there was a whole bunch of entertaining backstabbing drama going on in the industry, according to some of the reviews.
There's also a history of the gaming convention GenCon (
Wikipedia), and some books where designers discuss their top 100 hobby and family games (not just RPGs, but also including classic board games).
This seems pretty interesting even though I personally don't do tabletop RPG, but I really like micro-histories, so I splurged. Top-tier is currently under $19, and there doesn't seem to be a way to top up the lower pledge for the basic level, so be sure which one you want, and the 4 Designers & Dragons books are available in an ePub/Mobi/AZW3/PDF bundle, while the others are PDF only.