Sanhedrin 65b - Doing Magic

The gemara says that מעונן refers to אחיזת עינים, meaning it refers to making something look like magic, even though it is just an illusion. Based on this, the Chochmas Adam (89:6) writes that this would include illusions such as turning a rope into a snake, or throwing a ring up and make it look like it is being spit up by someone. He continues to write:

ומזה תראה שאותן הבדחנים שעושין כדברים אלו על החתונות ונקראין טאשין שפילער, עוברים בלאו דאורייתא והמצוה לעשותן עובר משום לפני עור, ולכן מי שבידו למחות צריך למחות וכ"ש שאסור להסתכל ולראותם, אבל אם הוא גוי שעושה נ"ל דמותר לראות

Based on this it would be an issur d'oraysa to hire a Jewish magician, and certainly to be a jewish magician, but one may watch (and maybe even hire) a non-jewish magician. Perhaps the chochmas adam would permit hiring birthday party magicians who don't do any spectacular copperfield style tricks. Rashi writes that the issur is that - ומראה להם כאילו עושה דברים של פלא. It would seem from rashi that if to the average person the trick doesn't seem supernatural, it would not be a violation. See also Igros Moshe (y.d. 4:13:1) where he explains based on the teshuvos ha'rama (he tries to be work out the contradiction in the Rambam whether there is malkus for achizal aynayim by saying that there are 2 types, one through kishuf and one using some other means that is actually doing something), that אחיזת עינים doesn't refer to quick movements that merely give the illusion of tricks as the shach and chochmas adam explain. With this he justifies the minhag of using badchanim at weddings, against the p'sak of the chochams adam.

In general regarding the sorcery prohibitions discussed in the gemara, the Rambam (Hil. oved chochavim 11:16) writes that they are all nonsense and were only used as tool to gather followers - ואין ראוי לישראל שהם חכמים מחוכמים להמשך בהבלים אלו ולא להעלות על לב שיש תועלת בהן וכו' כל המאמין בדברים האלו וכיוצ"ב ומחשב בלבו שהן אמת ודבר חכמה אבל התורה אסרתן, אינן אלא מן הסכים ומחסרי הדעת ובכלל הנשים והקטנים שאין דעתן שלימה, אבל בעלי החמכה ותמימי הדעת ידעו בראיות ברורות שכל אלו הדברים שאסרה תורה אינם דברי חכמה אלא תוהו והבל

The Rambam takes a very strong position that anyone who believes in magic is essentially a fool. But the GR"A (y.d. 179:13) writes that there are many sources in shas, including our gemara where the amoraim ate the calf that they created which confirm the power of this magic. The Rambam denies this only because he was convinced by the philosophers of his time. The gr"a prefers to understand the gemara literally, not allegorically and therefore holds that the Torah forbade this types of magic even though they actually work.