In addition to Bloomsbury’s publishing update from this morning, Pottermore has revealed today that Harry Potter and the Cursed Child will be published as a Special Rehearsal Edition book on Harry and Jo’s birthday – July 31st 2016. This will not be a traditional book, it will be a version of the script that was used during previews of the play. Plays traditionally make small changes throughout previews, so the book will then be updated to reflect these changes. According to their post:

Print and digital editions will publish simultaneously after the play’s world premiere this summer, and will comprise of the version of the play script at the time of the play’s preview performances.

Theatre previews allow the creative team the chance to rehearse and explore scenes further before a production’s official opening night. Harry Potter and the Cursed Child opens for previews several weeks before its official first performance on Saturday 30 July and the Special Rehearsal Edition of the script book will later be replaced by a Definitive Collector’s Edition.

The play opens in London’s West End this summer, based on an original new story by J.K. Rowling, Jack Thorne and John Tiffany. It is officially the eighth story in Harry Potter canon and a new play by Jack Thorne.