With this system, you would literally have an ace in the hole for survival (along with a club or two).<br><br>Honestly, though, your concept sounds a bit gimmicky, although perhaps useful for some people. Concentrate on the fundamentals. I would prefer a set in which the cards could be trimmed to provide firestarter, perhaps one or two with a reflective backing for a signal mirror, though I wonder if you could produce a product that would be reflective and durable enough to work well.