Munroe announced in March 2014 that he had signed a deal with publisher
Houghton Mifflin Harcourt to compile a large number of his
What If? entries into a book.
What If?: Serious Scientific Answers to Absurd Hypothetical Questions would eventually be released in September that year. The
What If? book contains a selection of questions and answers from the original blog, as well as nineteen new ones. Furthermore, Munroe selected a few unanswered questions from his inbox and collected those in separate sections in the book.
Alt text, which was commonly used for illustrations on the original blog, was omitted from the book in many cases, though is sometimes included as small captions underneath the images. Instead, Munroe has added
footnotes to the essays in the book to inform or entertain the reader. The cover of the book depicts a
Tyrannosaurid being lowered into a
Sarlacc from
Star Wars, a topic not covered in the book.
What If? is Munroe's second published book, his first being
XKCD: Volume 0, a curated collection of
xkcd comics released in 2009. Munroe released a third book, titled
Thing Explainer, in 2015, and a fourth book titled
How To in 2019. A sequel,
What If? 2, was announced in January 2022 and was released on September 13 that year. In May 2024, Munroe announced a 10th anniversary edition, with the book being released on November 26th of the same year. == YouTube Series ==