Portable Magic, by Donald Tyson
I wax hot and cold on Donald Tyson. First, I remember strongly disliking The New Magus when I first read it many and many a year ago. But I developed a stronger fondness for him after his editing job on Agrippa. Portable Magic seems like a really cool idea — using tarot cards as vehicles for magic. And the execution is excellent. He sets up a whole ritual system that seems very well-thought-out and clever.
My only criticism is that it’s a system that could be explained (at least to someone familiar with ritual magic) in a five or ten page pamphlet. There are other interesting uses of the cards that he never touches on (like, what about using them to develop the siddhi associated with the paths? What about using them in conjunction with the Hebrew letters to make sigils or words of power? What about invoking them as archetypes?).
I’ve tested the system, and it works pretty well. It just seems to leave so much depth unplumbed. Ah, well. For what it is, it’s worth the money, and I recommend it.