Gambling was basically prohibited and heavily punished in Venice, it was destabilizing business, and of course it was helping out any possible extra marital affair.
Gambling was allowed only underneath the Two Columns in St. Mark's Square, quite uncomfortable and not classy for sure. Something more for passing-by sailors and city visitors.
We can visualize here the atmosphere inside the Ridotto di Palazzo Dandolo a San Moisè, being everybody extremely elegant, classy, as it was Venice in the XVII century, after all.
Besides being recognized by the law as a "Public Casino" not really everybody would be accepted there, especially because of its Dressing Code.
