To dream of a casino represents a mindset that is always taking chances. Constantly trying something new or seeing what happens. Testing your luck or experience to see if you can benefit at all.
Negatively, may reflect a mindset that is taking too many risks over an extended period of time. It may also reflect a mentality that is taking too many dangerous risks. A sign that you need to find more secure options or habits.
Example: A man dreamed of being in a casino. In waking life he was regularly participating on a internet help forum to see if he could actually help someone. reflected his mindset being open to “seeing what happens” as not every person had an easy problem.