What is the magic behind them. Is it good, neutral, or black magic? I have been exposed to fortune telling cards for a very long time. I have personally practiced Cartomancy for more than 5 years.
I can tell you from firsthand experience. I have had no negative experiences with them. For I have learned how to properly ask a question and how to properly read the answer. Which is very accurate and true.
My cards are not a standard set that most people would see and use. I use the "Russian gypsy fortune telling cards" which can be found on Amazon. These cards must line up to give you an answer. What makes mine different, is that they are a copy on custom paper hand crafted. So they bond to me. The paper is like cardboard tough and durable.
They are not black magic. From one year I have dabbled with tarot and Lenormand and feel these to be beneficial. I know of another forum member who is a psychic.