While laden with allusions to the works of Lovecraft, this rule book focuses on simulating cats in the liminal zone between realistic and fantastical, very definitely giving it the feel of Eliot not Ulthar.
The world faces many threats, from the mundane dog to the eldritch Snarlyhotep and Phatproggua. While saving civilisation from these threats and those who worship them can get in the way of watching a really good piece of fluff, civilisation is where the comfy furniture is. This roleplaying game allows players to take on the characters of regular cats who have temporarily gathered in the same place to defeat a threat.
Attempts to perform an action being resolved use either a few dice or a small amount of play acting, such as the player having to hold a pencil in their mouth if they wish their character to carry an item or having to speak only in cat noises if they wish to communicate with a character that can’t see them. Characters do not have any numerical stats that would modify the value of a dice and a success always occurs on a 4+, because cats don’t do mathematics. Thus, while the rules refer to using six-sided dice, players could equally use other even-sided dice, or coins or other ways of generating a 50/50 chance. Combined with a couple of rules that change the default of two dice, vary the number of successes needed to achieve really important goals, or grant automatic successes, the system is extremely light.
Each character has one of five roles that indicate which aspect of being a cat they are especially good at (such as catcrobat or scrapper), one of three backgrounds that indicate their relationship with human society (such as feral), and is either pure- or mixed-breed. Each of these grants a small advantage, such as a catcrobat being able to test for acrobatics even when it should be beyond a cat, and combine into a backstory that allows the player to suggest something about the setting or situation based on what their character has previously experienced.
Although the entire game is based in genuine cat behaviour seen through the lens of affection, creating a pervasive sense of whimsy, the rules based around play-acting veer even more strongly into the humorous. They also unfortunately do not merely weaken the ability to play a character skilled in areas one is not but impose a non-trivial accessibility issue. For example, determining how long a character can hold an item by how long a player can keep a pencil in their mouth does somewhat evoke the issues cats might face having to use their mouth rather than a hand or pocket, but also fails to accommodate even the common category of players who like to drink some water at various points throughout a session. Fortunately, the simplicity of the dice roll mechanic makes it almost trivial to house-rule tests to replace the play-acting without risk of unfairness.
Thus, players seeking a game about cats (rather than anthropomorphised cat-people) are likely to find this book provides the light but engaging experience they seek as is, or that replacing certain rules with the basic dice mechanism allows a darker tone.
However, where the book does fall considerably short of what the description claims is in cosmic horror. Certainly, the rules do not prevent a game about cats fighting eldritch horrors and their cults; but a games master looking for anything that actively supports it, such as roles for monsters or cat-centric plot ideas, will find nothing. While converting monsters and scenarios from other Lovecraftian games and stories is unlikely to be taxing and might even offer a pleasing new perspective on them, using a title, cover image, and description that emphasise the cosmic horror aspect, then directing games masters to a companion volume rather than including at least a few rules and ideas in this one could feel like a bait-and-switch.
Overall, I found this rule book a light but not simplistic system, and solid feline setting guide. I recommend it to people seeking to play one-offs or short campaigns about mostly realistic cats.
Davetopia 
One thought on “Call of Catthulhu, Book I: The Nekonomikon by Joel Sparks”