May one watch or perform a mentalist or illusionist show?
Mentalist – If the performer clearly attributes their results to natural skills, such as the ability to read body language or to manipulate the subject subliminally through psychological suggestion, then it should be permissible.
Illusionist – It is permissible to perform, watch, or bring out an illusionist (which is done with Tznius of course) only if the magician explains to the audience that everything is sleight of hand tricks etc. and that none of the magic is real or possible. Even better would be if he demonstrates how one trick is done.
Many Poskim permit if it is done by a non-Jew.
Shulchan Aruch Yoreh Deah 179:15. Shach 17. See Igros Kodesh vol. 16 page 30.
Igros Moshe (Y.D. 4:13). Divrei Yatziv Y.D. 57. Teshuvos Vhanhagoes 1:455.
Through a non-Jew: Yabia Omer 5 YD 14. Chazon Ovadya Shabbos 3:501. Kovetz Or Yisroel 36 & 37.