The Masks of Nyarlathotep campaign for the Call of Cthulhu role-playing game is often cited as one of the best campaigns ever, a globe-spanning adventure that takes the investigators from New York to London to Cairo to Nairobi to Shanghai to Western Australia’s Great Sandy Desert. For seven long years the Call of Cthulhu RPG enthusiast site Yog-Sothoth has been working on a mammoth companion, featuring supporting details for the locations, advice on running it, side-journey scenarios, and more, intending for Chaosium to publish it as a monograph, with proceeds to benefit the site.
A draft PDF has now been released, weighing in at more than 500 pages.
Meanwhile, Pelgrane Press is producing their own ginormous globe-trotting campaign for Trail of Cthulhu, Eternal Lies, available for pre-orders, with the book scheduled to come out in August. I’ve briefly looked at the not-final PDF they circulated to pre-orderers, and it looks like a good time.