Shadows of Yog-Sothoth was the first adventure campaign for Call of Cthulhu published by Chaosium. The book consists of seven sequential adventures in various locations around the globe that pit Investigators against the Hermetic Order of the Silver Twilight. The cult is attempting to raise the lost city of R'lyeh from the depths of the Pacific Ocean, which will release the Elder God Cthulhu from captivity, destroying humanity in the process.
The book also includes two bonus stand-alone adventures: "People of the Monolith"; and "The Warren".
In the February 1983 edition of The Space Gamer (No. 60), William A. Barton recommended the book, saying, "Shadows of Yog-Sothoth should provide some exciting CoC play for even the most experienced investigators (despite the odd fact that Yog-Sothoth never makes an appearance, title or not), and I recommend it to all Lovecraftians."
Ian Bailey reviewed The Shadows of Yog-Sothoth for White Dwarf #44, giving it an overall rating of 10 out of 10, and stated that "All in all the Shadows of Yog-Sothoth is an excellent and masterly campaign that demands a high standard of play throughout. It is well presented [...] and carefully managed throughout, and it provides, I believe, the most exciting and satisfying adventure available on the market to date. It might seem expensive but it is worth every penny."
In the January 1984 edition of Dragon (Issue 81), Ken Rolston pointed out that "considerable study and preparation by the GM will be necessary... The tactics of the antagonists are not adequately detailed, and will need to be improvised or planned ahead." Rolston thought the first adventure of the seven was the weakest, but found the rest to be of superior quality. He concluded that "The adventures are unusual and the atmosphere exotic and terrifying. Yog-Sothoth is a classic example of role-playing horror, with awesome monsters, desperate victims, and an atmosphere of mystery and menace. Since it provides enough material for a campaign of several months’ duration, it is an excellent value."
In the June 1990 edition of Dragon (Issue 158), Jim Bambra called Shadows of Yog-Sothoth "good, but it is not as slickly written or plotted as [another Chaosium publication] Masks of Nyarlathotep"; but he admitted that it contains "excellent scenes" where "horror elements are well presented." Bambra also pointed out that the seven adventures could be de-linked and presented separately: "The individual adventures contain excellent scenes and can easily be run as one-off adventures if the Keeper doesn’t want to link them together. The horror elements are well presented, and the adventures span a wide variety of locations and investigative approaches." He concluded, "Opportunities for role-playing, investigation, and combat abound with nameless horrors and the depraved cultists who worship the creatures of darkness."
- Different Worlds #34
- Bambra, Jim (June 1990). "Roleplaying Reviews". Dragon. Lake Geneva, Wisconsin: TSR (#158): 89-90.
- Barton, William A. (February 1983). "Capsule Reviews". The Space Gamer. Steve Jackson Games (60): 49–50.
- Rolston, Ken (January 1984). "Role-playing reviews". Dragon. TSR, Inc. (81): 76–77.
- Bailey, Ian (August 1983). "Open Box". White Dwarf. Games Workshop (Issue 44): 12.