I really love Trail of Cthulhu. I think it manages to capture the feel and style of HPL’s stories, particularly when played in Purist mode, with rules built to complement the stories. GUMSHOE is a perfect fit for investigative type adventures, and well-suited for a plotted out set of scenes. It also is simple enough to be run in a more “off-the-cuff” improvisational style and doesn’t require a great deal of prep on the part of the Keeper, an important consideration for those of use with other daily commitments. That said, I think ToC works best when played in Purist mode because, frankly, if I wanted to play a really pulp-inspired game, I think there are better systems (e.g., The Dresden Files RPG which is uses FATE) that I would enjoy more. It’s not that ToC’s pulp-mode is bad – in fact it’s pretty cool – it’s just that I think where the real magic lies is in a purist-style game where investigators are outclassed and the emphasis is on investigation and running away. Your mileage may vary of course.

One common criticism of the system that I’ve heard is that it’s very “railroady” meaning that players are locked in to a set of predetermined scenes and outcomes that they have little to no actual control over. However, this criticism seems to be based largely upon a complete misunderstanding about the purpose of the “you always find the core clues” approach to investigation: finding the core clues is not meant to force players in to one particular direction – in fact, the most critical part of the investigation, namely interpreting the clues and figuring out what they mean, is still 100% in the hands of the players. Instead what GUMSHOE is doing is putting the vital pieces of information into the hands of the players so that they can actually make decisions and do something – gone are the days where a failed perception check leads to the group not finding the secret door and thus never discovering the hidden laboratory. In addition, it’s important to realize that the typical ToC adventure is based on constructing a “spine” of events or scenes, but that this framework is not a rigid, linear one. Characters can bypass whole scenes or complete them out of order – in fact one of the purposes of Investigative Ability point spends is to provide additional information or details which let the story branch in various ways. Thus, the whole “ToC adventures are built on rails” is completely wrong and instead what you have is simply a system that guarantees that players will have enough information to solve the mystery but not that they will actually come to the correct conclusion or succeed in the end.

Another factor that make ToC simply a great RPG is the quality of the supplemental material that’s been published to support the system: all of the adventures published to date are excellent (I can especially recommend Graham Walmsley’s adventures if you enjoy HPL-inspired Purist adventures) as are the other supplements. While none of the material is essential, it’s all very interesting and useful and largely aimed at helping support campaigns rather than providing an endless series of splat books. In addition, some of the material put out for other GUMSHOE games might also be of interest; in particular the Book of Unremitting Horror is a great source book for adding very disturbing, odd, or horrifying creatures – this stuff is all original and very strange which makes it a good fit for the Mythos and will keep even the biggest Mythos expert on their toes.

Finally, I would be remiss if I didn’t mention that the huge volume of material that Chaosium has published over the past three decades can also be used with ToC. While the game mechanics are quite different (ToC does include a basic conversion guide in the ToC appendices on how to convert BRP to GUMSHOE), the vast majority of these publications are system-less fluff and source material and thus very handy.

In the end, ToC is a game I would highly recommend to anyone who is interested in Lovecraft’s stories, or horror investigation in general. The game’s system, setting, and supplemental material all work together to create an interesting and thoroughly compelling world to explore.

You can read the complete review on my blog: http://rpg.brouhaha.us/?p=4316