Affiliate disclosure

Owlglass is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.

As an Amazon Associate, Owlglass earns from qualifying purchases. When a game links to a book on Amazon and you buy something after clicking, we may earn a small commission. It costs you nothing extra.

The books are picked because they belong in the game: a real bestseller that used the pattern you just chose, or a real history of the habit you just gave your ruler. Nobody pays to be included.