Boston Unveiled is the default setting book for Mage: The Awakening. These books serve a couple of functions. The most obvious is to provide a developed setting for chronicles, to save storytellers a bit of time. The other is to provide examples of the ways that the rules can be used, and the sorts of characters you might create. On the whole, I think they are more successful in the second role.
This book is no exception. As a collection of example mages and cabals, it does a very good job. It fills in the details of what the Awakened might do with their time, or want from their power, and, naturally, makes them all slightly tainted, because the series is essentially a set of horror games. The non-mage ideas are also good; I particularly like The Prince of 100,000 Leaves, an imaginative and terrible horror. That’s an idea that I immediately want to steal.
However, I’m not sure that they work so well in the first role. The problem is, I think, inherent to the form. They fix the broad outlines of the chronicle, but leave most of the details to be filled in. However, designing the broad outlines is the fun and easy part; it’s filling in the details that takes time and effort, at least for most people. On the other hand, it’s very difficult to do the details without the broad outlines.
I think the Tribunal books we do for Ars Magica are a bit more useful, because they provide a lot of information on the history and medieval myths of the area, and that saves storyguides a lot of research. But, fundamentally, they suffer from the same problem; they run the risk of cramping the storyguide’s style without saving him a lot of time.
This is not, therefore, a criticism of this book. I think it’s a good book for Mage, and very useful for people playing the game. I’m just not sure that it actually achieves, or can achieve, the ostensible aim.