In 2021, Greg T. Karber, a screenwriter and maths tutor based in Los Angeles, created a logic puzzle game named Murdle while sitting in a café. Murdle, which combines elements of murder mystery games like Cluedo with a Sudoku-like grid, requires players to determine the perpetrator, weapon, and location based on given clues. Karber further developed the concept by writing software code to automate and error-proof puzzle creation and set up a website, murdle.com, to offer these puzzles daily for free.
The concept gained traction and soon caught the attention of literary agent Melissa Edwards, leading to the transformation of Karber's idea into a puzzle book. Published in June, with sequels and variations including a children's version following closely, Karber's Murdle books achieved significant success. Notably, it appeared on the UK bestseller list for 38 weeks and was the top-selling book in the UK over Christmas, surpassing sales of well-known titles. The Murdle series boasts high sales, particularly impressive given Karber's status as an American author succeeding predominantly in the UK market.