How can randomly drawn cards have any relevance to someone's life and what's happening in it? What most readers say the Tarot can enlighten you about are the choices you have. The cards don't tell you what you should do or what specifically is going to happen in your future, but rather the possibilities depending on the path you take. Let's look at some of the theories behind how Tarot cards could possibly work.
Carl Jung believed that in addition to the repeatable cause-and-effect relationships on which the scientific world is so strongly based, there is also another connecting principle that does not share that cause-and-effect relationship. He called this principle synchronicity. According to Jung, synchronicity explains the guiding forces in the universe. Things we might see as coincidence are actually signs that can help us make decisions and guide our lives -- if we recognize them.
Jung believed that quantum mechanics could be a possible explanation for the phenomenon of synchronicity. (Quantum mechanics explains the relationships of particles and their random interconnectivity, with behaviors being probabilities rather than certainties.) There are those who believe that because the forces of quantum mechanics affect the reality of physical objects, Tarot cards might play the role of showing us paths and patterns and helping us understand the meaning in those guiding energies. Although, according to the principles of quantum mechanics, once you see the possible outcomes in the Tarot reading, you've changed the probabilities. While Jung did not study Tarot, he was interested in I Ching (another divination tool) and suggested that synchronicity could be an explanation for how I Ching might work for divination.
Some say it all boils down to your subconscious mind. Arguably, how we perceive things relies heavily on our subconscious, and there are those who believe that with Tarot, the subconscious projects its own interpretations on the Tarot cards. As a person receiving a Tarot reading, your interpretation of the cards is a result of the factors in your life that shape who you are and what you are about. The questions you have about your life (usually the reason for consulting the Tarot in the first place) are projected onto the pictures, so you divine answers from what you see. In this way, the Tarot is useful in helping us to tap into our subconscious to find answers that we might never consciously think of. The Rorschach inkblot test uses a similar principle to look into the subconscious. Whether you believe that Tarot cards hold any power or ability to shed light on your life, your problems or your future might depend on how easily you can open you mind to the idea of it. Many Tarot-card readers have differing ideas about how or why the Tarot works. In fact, some say we only need the Tarot to help us until we learn to get in touch with our "inner guide" on our own.