This is not the kind of question which can be answered in the forum, if you are thinking on opening a casino then it is better that you take this question to your lawyers and see if in the jurisdiction in which you are located you need one.

If you do not need it then you just saved yourself some trouble, however most likely you are going to need one if you want to serve people from the majority of the countries around the world, so maybe it is a good idea to just get one and save yourself a lot of headache in the future.