I was in Venice many years ago and went to the Casino in the evening dressed in jacket and tie-played and collected the chips that I wanted. The next afternoon we were walking by the Casino and I decided to get more chips. I was wearing chinos & a ss shirt.I went into the Casino and they rented me a sport jacket at no charge-I had to leave a €50 deposit which was returned when the jacket was brought back.
I was there in 2007 - the dress code was more relaxed - no tie needed-not sure about the jacket.