cold reading

1. The reading aloud of a script or performative text, as for television, theater, or film, with little or no rehearsal, practice, or study in advance. It's always a little awkward doing a cold reading for the first time, because you know things will be much different once everyone has had a chance to get familiar with the script.

2. A technique or series of techniques used by paranormal performers (such as mentalists, psychics, spiritual mediums, fortune tellers, etc.) in which the appearance of clairvoyance is achieved by gleaning personal details about a subject through the use of intuition, broad questions, and educated guesses and assumptions. It's amazing how convincing psychics can seem when all they're doing is giving a cold reading of people in the audience. I can't believe you fell for that fortune teller nonsense—it was just a cold reading!