I was immediately deeply impressed with the cover art. It is complex and stunningly beautiful. This will look great on a retailer’s shelf and, subsequently, on the gaming table. The interior art maintains this level of quality.
The layout is clean and concise, without the unnecessary clutter some publications have in an effort to look cool. I need a reference book to make it easy to reference the material, and this book delivers. The chapter headers and the topic headers and sub-headers are very easy to distinguish and the font is elegant. The chapter title pages also have simulated “big red bookmark ribbons” which I think look really cool.
The tables are quite easy to read and the “grey boxes” are clean and contain the information you need without a lot of flavor-text clutter.
The content is refreshingly expanded without excess complexity. The spells in Call of Cthulhu have always been simply “Spell A works like 1, 2, 3 . . .”
State of mind, sacrifice, astronomical considerations, “a clean space” and other factors acknowledged by magical traditions all over the world are discussed and, again, not belabored. Spell categories and information on magical traditions other than obviously Mythos is a wonderful and helpful addition.
Material components, locations with higher magical potential and/or space-time fabric integrity loss due to excess magical activity are discussed. The book is clear that these may or may not be desired by the Keeper, balancing between enhancing story intensity or diminishing game pace.
One issue Call of Cthulhu rule books have always had is the excessively random nature of the tables included. The text in the “Grand Grimoire” does inform the Keeper to use these examples for inspiration in preparing scenes and adventures, but I feel there is still too much danger of the Keeper feeling the need to roll on the fly.
This often causes unsatisfying results which have no bearing on their causation. Uncontrollably vomiting a huge stream of scorpions can be very fitting, disturbing and effective when a summoning spell goes awry, but not so much in the case of a failure to successfully cast Alter Weather. (These examples are my own creation.)
All in all, this book has been desperately needed by Keepers for decades and is a huge bargain at twenty bucks for the PDF. Speaking of which, here’s an important quote from the Chaosium website:
“Note: This product is a PDF File. A physical version of the book will be released later this year. Purchasing the PDF on chaosium.com will entitle you to the full price of the PDF off as a discount if you purchase the printed book on chaosium.com”