AUTHOR’S NOTE: During a recent conversation in the online tarot community, the questionable accuracy of long-range forecasts came up for discussion. The idea of intervening variables was mentioned, those unexpected changes in circumstances that can render a prediction invalid before it fully matures. I made the following observations (slightly edited for this essay):

The main variables as I see them are: 1) the farther out in time we go from the date of a reading, the less precision we can expect due to stray events arising from our unplanned actions (or imprudent inaction); 2) the intervention of other people with a competing agenda; and 3) deviation from the “script” by later developments of an impersonal nature (our private reality may have “gone out of sync” with the universal order of things). I think of it as “metaphysical entropy.”

One definition of entropy is “the unpredictability or uncertainty of a random variable,” and one common interpretation is “the tendency for systems to move from organized to disorganized states.” To the extent that a tarot story-line can be viewed as reflecting an “organized state” with well-defined expectations and a coherent time-frame for resolution, it can be construed as vulnerable to the phenomenon of entropy. Trying to introduce more than nominal indeterminacy into the narrative with what I call “weasel-words” can seem like hedging to an observant querent.

This speaks directly to the question of why tarot readings are so often incorrect in their details. Despite the caveat that the future is never carved in stone, beginners tend to anticipate more truthfulness from the tarot than it is capable of delivering because sometimes the “rug is pulled out from under” the original basis for the projection. A card may indicate one thing but its opposite transpires as the situation unfolds. Assuming that the diviner correctly interpreted its customary significance, there is no help for this kind of uncertainty so we just have to accept it as a common hazard of all divination.

A reasonable form of defense is to avoid being too prescriptive in the foretelling of events and circumstances. We can talk about tendencies, trends and possibilities shown by the cards that offer opportunities for the sitter to take specific actions, capitalizing on them or deflecting them as necessary; we can encourage an open-ended flexibility in coming to grips with what the reading portends; we can explore options or parallel paths that could lead to a less ordained conclusion; and we can consider alternate definitions that moderate particularly assertive cards. There is always room to distinguish between likelihood and speculation, making sure to draw a clear line in the sand.

Above all, we can assume that the analysis will unravel if the window of applicability closes before things have a chance to work themselves out. This can happen at any time due to unforeseen eventualities that shift the trajectory of the matter to the point that the previous course is no longer viable. We can apprise our clients of the potential but we can’t give them any more than a heads-up to be alert for surprises even if none are predicted at the time of the reading.