The description for this trick is more clever than the method. When reading the description my head swirled with solutions. This was based on a "subtle principle"! it has to be interesting. So I contemplated it's construction. Will it be reminiscent of a Martin Gardner or Bob Hummer effect with the spectators placing and moving coins around the triangle in a procedural way? Will it have a cunning logic puzzle solution to discern the coin and colored spots like the truth/liar puzzle? Will this rely on a certain placement or revelation of information that the spectator unknowingly provides to the performer? Maybe an interesting force? Hmmm...What was the "subtle principle"? I was curious. As a collector of methods, I paid the meager $4 to test my solutions (solutions that ruled out rudimentary approaches like a confederate) and learn something new.
First off this is short document. Eliminate the cover and the triangle page and you have a one page trick. That's fine. There are some very clever tricks that only need one page to provide adequate instruction. The instructions are pretty clear. It is bare bones. No patter or script, just description. The "method" itself is quite sparse with no tips to help in execution.
The cost is... well... $4. It is not costly but given the method it is expensive enough to be annoying.
So what is the method? Like it reads it's a "subtle principle". So we have to examine that phrase. First, it's not a new principle, or even a clever principle. In fact, it's not technically a "principle." That would indicate that it relies on a system. It doesn't. As for the word "subtle," it would be correct to describe a requirement of the method to make the trick work. But their lies the problem... the method. It is both glaring and uninteresting. It is the flaw in the design of the trick, a design that doesn't feel thought out. A flaw that tries to hide behind the use of the triangle, which is unnecessary to the "subtle principle."
The most unfortunate part of the product is that if the creator had created a new principle or had applied an old principle in a clever way that it spurred new possibilities then this would be a better product. But neither happens. In the end it is a flimsy Cracker Jack box trick disguised with clever ad copy.
