Carl Sanford Joslyn "Sandy" Petersen is an American game designer. He worked at Chaosium, contributing to the development of RuneQuest and creating the acclaimed and influential horror role-playing game Call of Cthulhu. He later joined id Software where he worked on the development of the Doom franchise and Quake. As part of Ensemble Studios, Petersen subsequently contributed to the Age of Empires franchise.
It was interesting reading this because while it's fairly short (the book is 96 pages but some of that is adventures and designer notes) all of the basics of the more modern versions of the Call of Cthulhu RPG are here. There's everything you'd expect - creating investigators using stats and skills, various monsters from Lovecraft and co. to fight or run away from, the magic, the sanity mechanic that makes CoC so notable.
Sure, a lot of the details haven't been built out yet. There's a list of Mythos books but they take the form of a random roll table with just the mechanical detail, so if you don't already know what Das Unassprechlichen Kulten or the Book of Eibon are, you're SOL on details. The monsters are really just the most common, classic ones - Elder Things and Shoggoths and Deep Ones, without plenty of the stuff that allows later editions to have giant bestiaries of horrors. The gods are here too, and again there's a small number of them. Also the bestiary is purely Cthulhoid - you have to flip through the 1920s Sourcebook in the same box if you need animals or vampires, ghosts, and werewolves. Even the skill system and selection of careers feel anemic, focused mostly on tweed jacketed nerds who could get beat up by even a measly byakhee.
Which is not to say that I dislike this version of the game. In a way it's cool to see that you can fit the core ideas of this RPG into so small a space - it's like the Rules Cyclopedia edition of Dungeons and Dragons. All the stuff that makes the game a fun time is here, from the sanity system to the monsters to a good discussion on how to create scenarios as layered onions of conspiracy that can never be fully peeled back. Even before you reach the Designer Notes it's clear this book was a labor of love on the part of the creators. And there are some things I like about the minimalism. It's nice to have a smaller set of mythos monsters so that most of them stand out well - though a few of the blobby guys start to meld together. And I really like the pared down list of insanities here, as there's much less of the roleplaying real life mental conditions stuff there is in later editions. (Well, aside from the phobias, and even then they're a mix of common and ones suited to the particular milieu.) Plus the scenarios are a good selection and I enjoy seeing that The Haunted House has been around since the very beginning and once fit in about 3 pages.
Honestly, reading this has made me want to reread the 6th edition at some point so I can compare and contrast how that managed to turn into a 300 or so page book while still maintaining the same core rules and concepts. I got this version as part of the 40th anniversary classic rerelease Kickstarter, and though I'm not running out to try to get a game going, I do appreciate that if I want to with that box I've got a solid version of the rules and plenty of adventures to keep things going for a long time. Some anniversary edition rereleases feel a bit gimmicky but this feels like a game that would hold up pretty well even now.