Short answers, pulled from the story.
Guildmasters' Guide to Ravnica was published on the 20th of November 2018. The book serves as the definitive sourcebook for the Ravnica universe and transforms a card game concept into a playable campaign setting for the fifth edition of Dungeons & Dragons.
The setting of Guildmasters' Guide to Ravnica is a high-magic world with a loose Slavic flavor where a single city spans the entire planet. This city is controlled by ten competing guilds of different ideologies, each with its own army and secret agenda.
James Wyatt served as the lead designer on Guildmasters' Guide to Ravnica. He is a longtime Wizards employee who started writing free PDF releases called Plane Shift in 2016 to adapt Magic: The Gathering planes for Dungeons & Dragons.
Guildmasters' Guide to Ravnica introduces five new races including centaurs, minotaurs, loxodon, Vedalken, and Simic hybrids. The book also provides two subclass options, the Order Domain Cleric and the Circle of Spores Druid, along with about 70 pages of stat blocks for monsters and non-player characters.
Guildmasters' Guide to Ravnica is a substantial 256-page volume. It contains a ninety-page overview of the ten guilds and the Tenth District, nearly 40 pages dedicated to building adventures, and about 70 pages filled with stat blocks.
Guildmasters' Guide to Ravnica was nominated for Best Game Accessory in the 2019 Origins Award. The book was also named a Black Friday winner and appeared at number 17 in Hardcover Nonfiction in Publishers Weekly's Best-selling Books Week Ending the 3rd of December 2018.